It was around 4:30 p.m. on January 15, 2011. Leyton Orient's bullish centre-forward Scott McGleish saw his number go up and trotted across the waterlogged turf at Rochdale's Spotland Stadium to take up his place in the dugout and watch his side play out the final 17 or so minutes of a largely eventless 1-1 draw.

On in his place came a 17-year-old striker sent to the O's of League One by Tottenham Hotspur, just a few miles north of the club's Brisbane Road home ground.

The Rochdale game, according to Orient assistant boss Kevin Nugent, should never have gone ahead, owing to the torrential conditions and a virtually unplayable pitch. But, in making his professional debut, the Spurs youngster didn't stop running, not until the final whistle had put the 2,371 fans who had braved the weather out of their misery.

Harry Kane spent five months on loan at Orient in the second half of the 2010/11 season. He made nine starts in League One with another nine appearances as a substitute, and he scored five goals. He was booked twice and sent off once, that after collecting a second yellow at Huddersfield Town.

The season finished with Kane watching from the bench, an unused substitute in a 4-1 win at Plymouth Argyle—in which future Everton and Crystal Palace winger Yannick Bolasie scored for the home side—as Orient finished seventh in England's third tier. It would have been a bold assertion that said here was one of Europe's most refined No. 9s in the making.

There were few, if any at all, who predicted it, and certainly none who went on record. But no one who worked with Kane during his loan spells, first at Orient and latterly in the Championship at Millwall, was in any way cynical about the significance of the talent in front of them.

Speak to those who witnessed his rise and it's easy to get lost among the platitudes for the young Kane. He was a professional certainly, with a winning and willing attitude; he integrated well; his movement, touch and finish were all excellent and of undoubted Premier League quality.

Such was his work ethic that most days after training at Orient he would return to Tottenham and put in more hours with the coaching staff at his parent club. The O's agreed that since Spurs' under-21s weren't playing in league competition, their loanee could return to north London when they weren't involved in a game and play there.

"Football friends," as former Orient assistant Nugent put it in an interview with Bleacher Report, are the lifeblood of the loan market.

Nugent used his connections with, among others, Joe Jordan and Alex Inglethorpe—the latter of whom had played for Orient in the late 1990s and was part of the youth setup at White Hart Lane—to not just arrange the deal for Kane but to make sure the loan period ran smoothly with free and easy lines of communication between the two clubs.

Kane and the club had to fit together perfectly, or the deal might hinder rather than abet his progress. Spurs assistant first-team coach Tim Sherwood, who both Nugent and then-Orient manager Russell Slade had known for years, was another point of connection. So too Harry Redknapp, who had a longstanding relationship with Slade. The support networks that ran beneath Spurs and Orient, in other words, were steadfast.

"There were very good communications between the two clubs at that time," Nugent said. "It really fitted in nicely. The training grounds were so close to each other and we were able to have constant feedback going back and forth, they'd have people come down to watch our games when possible. It was just a great link between the two clubs."

The step down the divisions is a test of character for any Premier League loan player. There is a downgrade that must be adapted to, fewer staff to work with and drastically more-basic facilities. "I spoke to Harry personally about adapting to a new environment," Nugent said. "If you go out on loan to a club like ours you have to try and learn from every situation."

What are some of those lessons? Often it is simply a matter of a player accepting they're not in the side and dealing with disappointment in a mature manner, but many younger players don't quite know how to articulate that disappointment.

When that happens, young men—often deprived of their support network for the first time—begin to feel more conscious of being outside of their comfort zone. If a pattern takes hold, a crisis will not be far behind.

Nugent continued: "A lot of players think it's going to be easier than what it is. The style is very different from under-21 football, the pitches may not be quite as good, the facilities are poorer. There's numerous things about the change that can affect individuals. But Harry braved every situation.

"It helped that he was able to stay living where he was, and that's why it's important that the Premier League clubs make sure they're dealing with the right clubs they're sending them out to, somewhere that's going to look after them.

"It's about attitude. They have to embrace that sometimes it's not going to be perfect for them and they're not going to be in their comfort zone. But also it's about personality.

"Sometimes a parent club will want a young player to leave London for example because it's right for them, or they might want them close by because they think if we send him to say Scotland that'll kill him, he's not ready for that. But Harry embraced everything about being at Orient."

The old idiom that it takes years of work and dedication to become an overnight success is deliciously apt in Kane's instance. While the world scrambles to assess his development in hindsight, those who saw it up close were in the privileged position of being able to observe the rise of a superstar in real time, warts and all.

The first instinct for a coach or an old-headed team-mate is not to indulge a talented young player for the skills executed with aplomb, rather to dwell, to linger and to pick fault; to seek out room for improvement and how best to manoeuvre within it.

McGleish played up front with Kane at Orient. He turned 37 during their time together and was on his ninth club of a career that had already spanned 18 years. He recognised the talent in the Spurs starlet, but by no means through rose-tinted spectacles.

"You could see his ability," McGleish said. "The worry was, and this is an elder statesman who grew up watching Tottenham and Arsenal, he looked like a typical Tottenham player of the 1980s. Technically very good, physically fine but of a slowish sort of pace about the way they play. Like Glenn Hoddle, very elegant but running with the ball at quite a casual pace.

"And that's what I saw from Harry, he looked like a Tottenham player from the past with lovely technique, good finishing ability but would he be quick enough for the Premier League?

"All the Premier League has ever done each year is get quicker and quicker and quicker. Coming to us at 17, it was hard to see then that he was going to be this megastar. He was a young boy and it was a case of 'Would he get another contract?' more than anything else. But he was willing, and he went out to other clubs and was asked to play games rather than just sitting there playing under-18s, under-21s. He wanted to go and learn the physical side of men's football, and through that I believe it helped him.

"He's twice the size now that he used to be, in every aspect. He looks taller, he's a lot more physical, he's wider. I'm sure he's the same height but just his presence in his chest and in his shoulders, it makes him look that much bigger. And that comes from playing, from thinking, 'Hello, I'm getting pushed off the ball a lot here, I better do something about it.' His biggest asset was his attitude."

Attitude is a recurrent theme around Kane. During those months in League One, Slade and Nugent often dropped him into the No. 10 role behind a front two. This was by no means the player's preferred position, but there was a utility to deploying him in a dropped-off role, namely that his vision was better than most at that level of the game and he had the feet to act on what he saw ahead of him.

Arsene Wenger has repeatedly stated that a necessary rite of passage in any young player's first-team education is to harness adaptability, to learn to become useful all over the pitch. This will often be a chore. It is a mark of character how willingly a player works through this stage in their apprenticeship.

That adaptability was in evidence throughout Kane's time at Brisbane Road. He and regular strike partner McGleish would often switch roles during a game, alternating who would be the target man and who would drop off.

There were no fixed roles, no calling dibs on the goal-grabbing hot spots. In that sense, the old hand McGleish eased the young Kane into life as a pro, encouraging him to realise that even though his touch was better and his vision more penetrating, there was donkey work to be done all across the front line, and there was to be no swinging of the proverbial lead when it came to picking up the slack.

Then there was the fight in the dog. Some players, understandably if not necessarily excusably, arrive from the Premier League and expect to play each game on account of their parent club's reputation. Kane was never so presumptuous, retaining instead a sense of place and proportion and married a sincere willingness to fight for his shirt with a mature deference to accept being dropped with good grace and humility.

"Harry came in so young that he never expected to play every game," McGleish said. "So he fought with his performances to be picked to play in every game. It was him overcoming the stigma of where he'd come from, I think. He came in and decided 'I need to work. I need to do this to warrant a place.' And he did that.

"Don't get me wrong, he never started every game, there would be times when he played three of four consecutively and then the gaffer might pull him out. It's important to give Russell Slade credit. He pulled him out at the right time to give him the hunger and to make sure that when he came on he did well, and seeing that as a young 17-year-old he didn't want to burn him out too early.

"Orient and Russell managed him very well, in terms of when he played and where he was played as well. They deserve the credit."

Harry Kane's first professional goal was at Leyton Orient. #COYOS pic.twitter.com/Wz2d279Fen

— Elizabeth Todd (@ElizabethTodd_) February 26, 2017

The loan system is one of the great successes of football's sometimes dysfunctional bureaucratic skeleton. When it's not being abused and misused with the hoarding and lending of players who are never intended to be reared for the first team but simply to bump up their value, the mechanics have a natural elegance to them.

It's not all, of course, about the loanee and the long-term benefit to the parent club. With Kane and fellow Spurs youngster Tom Carroll in the side, Leyton Orient's 2010/11 season improved suddenly and drastically, from lower mid-table when the two arrived in January to the cusp of the League One play-offs —the team finished seventh by a single point from sixth-place Bournemouth—via an FA Cup fifth-round replay against Arsenal.

Kane watched from the bench as French forward Jonathan Tehoue headed an 89th-minute equaliser at Brisbane Road in late February to claim a 1-1 draw and set up a replay at the Emirates Stadium.

He was suspended for Orient's big day in north London—Kane would need to be patient for his chance to hurt the team from the red end of the Seven Sisters Road—but the season at large seemingly span on a sixpence from the turn of the new year.

Lee Butcher faced down Kane every day in training, the first goalkeeper to do so since the future England sensation had got the added buoyancy of first-team success under his belt. He remembers a seismic change the day the boys from White Hart Lane came to east London.

"He made such an impact in helping us when he came in," said Butcher, who was also in and out of the team during the season's run-in. "That was a great season for us, especially with the Arsenal tie in the cup, and he and Tom Carroll were a massive part of that. He [Kane] just wanted to learn; he would always stay after training, wanting to do a little bit more each day.

"Him coming from Spurs to Orient was great because he already knew a few people here, but I honestly don't think that mattered to him. Wherever he went he was going to put his head down and get on with it. That's who Harry is. He was quiet in the dressing room, very much on the periphery, but he just worked and worked and worked. Just got on with the football."

The platitudes pile up around Kane, but the focus and single-mindedness he displayed as a loanee should never be taken for granted. Plenty of talented young players are farmed out by Premier League clubs on lower-league apprenticeships and fail, coming back beaten and bruised, without the street smarts to patch up their battered egos. Many come much more vaunted than Kane was at such a young age. Overwhelmingly, if not exclusively, the problem is psychological.

"For a young player to get out on loan and play men's football is absolutely the best thing they can do," Butcher said. "For Harry, going all around the lower leagues has helped him massively. His attitude was right already, when he joined us. He's not big-headed, he's humble.

"And deep down now he knows that he's done the hard work; he's been out on loan, he hasn't just been able to step into a first team and play every week. And now he's the first name on the team sheet at Tottenham.

"Back then I saw him as a Teddy Sheringham-type player. He wasn't the quickest, but he was two yards in front of people because he read the ball. He could read the game so well and knew what was happening a couple of steps before anyone else. Whereas some players would use their pace to get around, he's already two yards ahead of them. He's already there. And he had that when he was with us at Orient.

"It's weird. When you're playing football, you can kind of tell how people read the game. And I saw it straight away in Harry. He had to be that way because he just didn't have the pace. At Orient we got to see that evolution of his game."

So keen are former team-mates and mentors to play up the young Kane's mental fortitude, tactical nuance and so forth that one can almost forget that which is staring us in the face; the goals, that ability to plunder and to create, a knack for the spectacular and an instinct for the devastatingly simple.

As a young loanee his great knack was getting a shot off early, catching the goalkeeper off balance, which is the X-factor when it comes to finishing, according to Butcher. Kane could always get a shot in while the goalkeeper was moving, taking away those necessary microseconds for the man in nets to get set and steady.

There's a caveat to that, of course. Often a team-mate in a better position could be overlooked, and it would be several seasons before a less-haste, more-speed philosophy could bed in. But the quickness of thought transferred readily to the feet was what characterised the young Kane. The shot always came, and invariably it came early.

Certainly this is how Kane's strike partner at his next loan outpost, Millwall, remembers it. Andy Keogh played with the Spurs man during the 2011/12 season, this time one level higher in the Championship.

"He always got his shot off," Keogh remembered. "Always. Left, right, centre; it didn't matter to him, he was brilliant wherever he shot from.

"He needed to bulk up a bit back then and obviously he's much leaner and more muscly now. I think a lot of that came with age. Or potentially even just from meeting the right fitness coach. But there was no part of his technical ability that was ever lacking at Millwall.

"It was after about a week that the manager threw us up front together. And all of a sudden Millwall were doing well, moving up the table. We had a great partnership.

"He was very mature for his age, and his understanding of the game was excellent. You would never have thought I was playing with an 18-year-old."

It was another midseason turnaround, just as had happened at Orient the season before.

Kenny Jackett's Millwall were on the lip of the Championship relegation zone when Kane and Keogh arrived at the start of January. After a slow winter the season picked up, and Millwall ended the season with six wins out of seven to finish a comfortable 16th, 17 points clear of the bottom three.

Kane signed off at the New Den with nine goals to his name, operating now only one division below the top flight. It was the successful step up Tottenham had hoped for.

"Everyone at Millwall knew he was going to be a top player," Keogh said. "I remember some of the lads saying he would go on and play for England. But then we also had Ryan Mason from Spurs as well at the same time and a lot of us said he wouldn't make it in the Premier League. So we were proved wrong on that front."

The final step into the Premier League was a protracted process. After Millwall there were spells at Leicester City in the Championship and a blink-and-you'll-miss-it three-game stint at Norwich City in 2012/13.

By that point, his first Premier League game had already been and gone, four minutes plus injury time at the end of Spurs' 2-1 defeat to Newcastle United in August 2012.

It wasn't until Mauricio Pochettino used the early games of Tottenham's 2014/15 UEFA Europa League campaign to blood Kane, giving him his first chance to score regularly for the first team, that something approaching the Europe-wide sensation began to reveal itself.

*All quotes and information obtained firsthand unless otherwise indicated.