Kemba Walker wasn't the first NBA player to lose more games as a rookie than in his entire amateur basketball career, and he certainly wasn't the first lottery pick to spend his rookie season playing for a loser. This is the sort of thing that happens when a league mandates that its worst teams be rewarded with the draft's top picks.

But you'd be hard pressed to find a player whose descent from winner to loser was more pronounced.

For one thing, by the time he entered the NBA, Walker had done more winning than most of his peers. In three years playing for the University of Connecticut, he led the school to a Final Four appearance, a Big East Conference Championship and, as a junior, an NCAA Tournament title. He was named the Final Four's Most Outstanding Player during that last run and, a few months later, in June 2011, was drafted ninth overall by the Charlotte then-Bobcats.

And then there's the other side of the equation. Walker didn't join just any retooling team. He joined one that dropped 59 of its 66 games during his rookie season (which was shortened due to a lockout), nearly twice as many as the total he'd lost (30) during his three years at UConn—good for the worst winning percentage in league history.

Some might have taken it all in stride, as part of the natural course of a career. Not Walker. The defeats drained him. "He's a guy who gets beat down by losing," says Gerald Henderson, who played four years alongside Walker in Charlotte.

30 teams, 30 days: The biggest story from each NBA team ahead of the league's return.

Atl | Bos | Bkn | Cha | Chi | Cle
Dal | Den | Det | GS | Hou | Ind
LAC | LAL | Mem | Mia | Mil | Min
NO | NY | OKC | Orl | Phi | Pho
Por | Sac | SA | Tor | Uta | Was

The low point came after one of the team's 29 home losses—no one can recall exactly which one. Chris Whitney, a member of the Charlotte coaching staff, found Walker in the locker room, screaming and weeping. Whitney had been around the NBA for a long time. He'd played for 11 seasons and was now in his second coaching. But Walker, Whitney says, "was the first NBA player I've ever seen, like, actually break down after a loss."

It would take three seasons for Walker to make the playoffs; five for him to finally win a playoff game. That victory came in 2016 when Walker helped the Hornets (who had changed their name from the Bobcats before the '14-15 season) push the heavily favored Heat to seven games. Losing that year stung. But the experience—one in which every possession of every minute of every game felt like it could alter the series—left a mark.

"That was one of the best times I've ever had playing basketball," Walker says now. "It was so competitive."

The Hornets failed to make the playoffs in any of the following three seasons. Walker was left watching from home—something he said last year he does "because I'm a big basketball fan, but that I hate because I hate not being there." Upon becoming an unrestricted free agent last summer, he signed a four-year, $141 million contract with the Celtics. The decision wasn't strictly his—the Hornets made clear that they would not be offering a max contract—but it still came with sacrifices. Walker gave up the comfort of spending his seasons in a city he's adopted at his hometown, the power of being his team's primary option and the freedom that comes with being a franchise's lone star.

He sacrificed those things so he could be where he is now, playing for a team that enters the restart as one of the few legitimate championship contenders and will almost certainly accomplish something Walker never has: advancing past the playoffs' first round.

"That's why I wanted to be here," the 30-year-old Walker says. "They do that every year."

Entering the March shutdown, Walker had provided the Celtics with everything they could have hoped—and they had returned the favor. He was averaging 21.2 points per game and drilling 37.7 percent of his deep looks. The 1.08 points he was recording per pick-and-roll possession was the league's third-best mark among players who ran five or more per game. His off-the-dribble prowess, deadly pull-up shooting and smooth scoots into the paint added punch and diversity to head coach Brad Stevens' attack. Walker's skill set also helped unlock the budding talents of Jayson Tatum and Jaylen Brown. The sum of it all was the league's fifth-best offense (after finishing 10th in that category last season) and a 43-21 record, good for third in the Eastern Conference.

But, Walker says, there have been bumps along the way. He spent the previous four seasons as Charlotte's main—and often lone—offensive engine. The team's primary scheme, because of Walker's prowess but also the lack of talent surrounding him, was simple: Give the ball to Kemba. No player ran more pick-and-rolls between 2016 and 2020, according to NBA.com's player tracking data, and only a handful had the ball in their hands for longer periods of time.

Walker knew that in Boston he wouldn't possess such freedom. It was a change he welcomed. The problem, he says, was that at times, his yearning to fit led to him passing up shots in a way he never did before. In response, Celtics assistant coach Joe Mazzulla has spent the year imploring Walker to shoot more—a request Walker hadn't heard in years. 

"You play with a bunch of new guys, you want everybody to feel good about you and you want to be cognizant of everybody," Walker says. "I think for me, I didn't want everybody to think that I was just a scorer or that I was selfish with the basketball."

Along with Mazzulla, Celtics forward Gordon Hayward has helped free Walker from such concerns. "He was always coming up to me, telling me that they want me to be more aggressive—they can tell when I'm not," Walker says. "He made me feel comfortable, which I really appreciated, especially early in the year. Just letting me know that nobody is going to say anything, and nobody is going to be mad at me for shooting [certain] shots."

Walker grew more comfortable in his role as the season went, but around the New Year another obstacle emerged: He started feeling soreness in his left knee, which had been operated on twice before. He missed three games in early January, another three a month later and then five after the All-Star break in mid-February. The knee was drained, and he received an injection to help relieve soreness and swelling.

Walker played just four games in February, and then another four in March. He was far from himself. His shooting percentages plummeted (31.7 percent from the field, 31.3 from deep). He struggled driving past defenders. The worst moment came during a game on March 8, when, with just 10 seconds remaining and the Celtics clinging to a one-point lead, Thunder guard Dennis Schroder stripped him in the backcourt. The turnover led to a layup and a one-point Celtics loss.

"My knee was definitely holding me back at the time," Walker says. Asked what specific actions he felt limited in, he replies: "Everything." He laughs, then offers one more-specific example: "Walking." He laughs again.

In a way, Walker says, the shutdown, which he spent holed up in his spacious Charlotte home, gifted him an opportunity. "That was great for me, to be able to rehab my knee and get myself back to feeling good again, which I am," Walker says. He also relished the chance to pick up some new hobbies. "I always wanted to learn how to play an instrument, and the piano was at the top of my list. So I've been really into that lately. I think I'm going to bring a keyboard with me to Orlando for the bubble." Walker's skills impressed his housemates. "I wouldn't say he's John Legend," says Grant Williams, a Celtics rookie who lived with Walker during the shutdown. "But he's getting there."

When not playing piano, or UNO with Williams, a trainer and a third friend, or H-O-R-S-E on Walker's outdoor court, or challenging his housemates to trick shots on the golf course, Walker would train at the gym of nearby Providence Day School, Williams' alma mater. Initially, Williams says, it was clear Walker was laboring. But he grew stronger and stronger over time, and the group's workout shifted from simple shooting drills to mimicking actions from the Celtics' playbook: pick-and-rolls, hand-offs, motion off down screens.

There were times, Williams says, when he wanted to ask his host what it was like to be preparing for a possible NBA championship run for the first time. "But he never brought it up and I left it alone," Williams says.

Walker's real test will come in the later rounds. It's not a coincidence that the Celtics have surrendered an additional 6.2 points per 100 possessions this season with him on the floor, according to Cleaning The Glass. Scouts and coaches around the league say they would be surprised if Walker, just 6'0" and 184 pounds, isn't targeted on opponents' pick-and-rolls every possession down the stretch of close games.

"I expect that," Walker says. "I really do. But at the end of the day, there are two sides of the ball."

Assuming he remains healthy, this summer could serve as a referendum on Walker's career. He's already proved he can be a great player for a bad team, but can he elevate a good one when the games matter most? Can his offensive punch make up for his defensive deficiencies when every possession matters? Can he navigate the balance between looking for his own shot and setting up others in games where there's little margin for error?

Walker says he's not concerned with such questions. He trusts the work he's put in. And anyway, he prefers to walk through life with a more optimistic outlook.

"I'm just really, really excited," Walker says. "This is something I've been waiting for for a very, very long time."

Yaron Weitzman covers the NBA for Bleacher Report and is the author of Tanking to the Top: The Philadelphia 76ers and the Most Audacious Process in the History of Professional Sports. Follow Yaron on Twitter: @YaronWeitzman.