Paul Scholes, like Ryan Giggs, has been a mainstay of Sir Alex Ferguson's Manchester United since 1994. But there will never be another one like him.

And in some ways United don't need a Scholes clone, like they don't need a Roy Keane clone. 

The game has changed.

But of course that is not to say that there isn't plenty of room for a consummate long- and short-distance passer who can put a ball on a sixpence.

The trouble is that with the density of modern day covering and marking there is less opportunity for the "marquee" pass than there was, unless you play for a counterattacking team.

Which of course United still are.

Indeed they are an attacking team in general. They try to win every match and probably use wide players as much as any top team in Europe. That is one of the scenarios where a player with a consistent ability to ping a long pass or switch the play has value.

However, even Sir Alex has implied that Nick Powell can be "the new Paul Scholes." What a tag to hang 'round somebody's neck!

So let's be clear, here. We are not conducting an "identity parade" to try to spot the next Paul Scholes. But what we shall be doing is considering the tactical nuances and some possible personnel to complete a jigsaw that may only be missing one or at most two critical pieces to achieve greatness.

So What Did Paul Scholes Bring?

David Beckham is also arguably one of the best passers in English footballing history. OK, so he played on the right wing for much of his career, but has also been effective in a deeper lying central midfield role.

However, whereas both he and Scholes can hit the ball 60 yards to drop in front of the striker, or a similar cross-field pass that switches the play, the similarity ends there.

Both of them admired Sir Bobby Charlton as they grew up.

And it is easy to forget that is the type of player Paul Scholes was for much of his career. He was at his best playing in the No.10 role or "in the hole," as well as ghosting into the box.

He was just as adept at heading a goal at the far post as he was hitting a 25-yard drive with either foot.

His role changed, particularly after Roy Keane left the club and as he got older, dropping back first to be a playmaker and then a deep-lying playmaker.

The problem has been in the last year or so that with Michael Carrick and Scholes being the supposed first-choice midfield pairing, Paul tended to play too deep, leaving a vacuum in front of them and sucking the opposition's midfield into it.

And of course he was never a great tackler. Indeed, the fans used to hold their breath as he shaped for a tackle because his timing was so poor and has got noticeably worse.

But wherever he played in his career, Scholes could pass or strike a ball with the skill and accuracy of almost anybody in the history of the game.

Short or long passes, his accuracy percentages are as good as anyone as well.

So How Will He Be Missed?

In some ways he won't now, except for his stellar career record and countless great performances.

Manchester United have already started to move on, and the game itself has changed in the last several years.

Of course a player like Scholes would fit like a hand in a glove in the present Barcelona team and would probably be able to extend his career by a couple of years if he were there.

He would also fit in the Swansea team for similar reasons but would not have the fitness to last 90 minutes because they play a pressing and harrying game as well.

One of Sir Alex Ferguson's great qualities has been his ability to completely change tactics and formations as he sees fit.

Nowhere was this more clear than in the second leg against Real Madrid. In the first leg, Phil Jones had been deployed to help nullify Cristiano Ronaldo. Patrice Evra and Rafael were allowed to follow the players they were marking all over the pitch.

And yet United should have won the match.

In the second leg we were trying to think who would play the Jones role, but Sir Alex outguessed all of us and even Jose Mourinho. He dropped Wayne Rooney and played Danny Welbeck as both a striker and to nullify Xabi Alonso, stopping Ronaldo's supply at source.

Meanwhile, he started Ryan Giggs on the right wing and gave him the freedom to use his intelligence either in defence or attack as appropriate.

It worked like a dream and, but for a crass refereeing decision, United would surely have walked away with the tie.

Frankly, even a fit Paul Scholes would not have fit in anywhere.

Indeed, even though Sir Alex had hinted at it before, we can go back to December 2011 when the manager hinted that Carrick could fill the vacuum left by Paul Scholes' premature retirement.

So in a way, United have already moved on, but any manager would find room for a Paul Scholes at the height of his powers. The difference is that now he would have to fit in with United's new tactical approach.

So What Do Manchester United Need?

By now you might be forgiven for asking where this article is going, given the title.

What we are implying is that United should replace Scholes with a player of equivalent stature or potential, but not a like-for-like replacement.

It should be a player with consummate skill and the ability to dictate the pattern of play and/or dominate a game as appropriate.

He should also be able to tackle and intercept.

Why? Well we're not talking about a hard or physical tackler but the ability to break up opposition play. Also the capability of sitting in front of the defence when needed and breaking toward and into the opposition penalty area when required.

An identikit player would have Andres Iniesta's playmaking, Giggs' dribbling and running, Scholes' passing, Carrick's intercepting and Steven Gerrard's tackling ability.

That player doesn't exist of course.

The other major consideration is to fit in with United's modern, dynamic interchanging and pressing style.

While most people appreciated Shinji Kagawa's technical skill from his time at Borussia Dortmund, many were asking when he was signed "where will he fit in?"

At Dortmund, he was often "in the hole" or creating or scoring goals.

United already had Wayne Rooney, and once they bought Robin van Persie we began to look for other positions Kagawa could play. Certainly, he could fit on either wing, but not in the way that Nani or Antonio Valencia do.

There was never any suggestion that he was a Scholes replacement. But against Norwich he finally fulfilled his brilliant potential, and we found out how he can play and the best way to use him.

So despite the new game of "spot the Paul Scholes replacement" many people have been playing ever since he announced his first retirement, we argue here that what United really need is a player commensurate with Scholes in all-'round ability or potential, but able to fit the way United play.

Who Can Fill the Need?

So to summarise:

We have concluded that of course United would love another player with Paul Scholes' all-round gifts, but that player probably either doesn't exist or would not be available at an economic price—or at all.

We also believe that they need one "marquee" player to complete the jigsaw and become a truly great team, whether that person is found from within the Old Trafford ranks, is bought young and developed, or is the finished article.

But we conclude that the modern game and United's style have changed and moved on, and whoever that person is must fit in and/or adapt to that style and those tactics and be able to assert playing authority over the game.

We're thinking here of a Michael Ballack, Diego Maradona or Andrea Pirlo-type authority, but not necessarily the same or similar type of player.

Indeed, they have to be a Manchester United-type of player and this is a key point. Why? Because that brings in the factor of a player adapted to United's playing policies, style and tactics.

Take the example of Anderson.

Some people have been bemoaning recently that what Sir Alex has tried to do with Anderson has detracted from what he had and what he did before he joined them.

He was a young, energetic, ball-playing footballer, already likened to Ronaldinho and who loved nothing better than to run at and destroy defenders.

The first thing Sir Alex did was to teach him to tackle. He also got Anderson playing deeper, covering and intercepting.

Of course, that was very different from the way Anderson was brought up, but the manager did want a long-term replacement for Paul Scholes—but not a clone. Scholes has never been able to dribble through a defence in the way that Anderson or Nani and even Ryan Giggs can.

So if Sir Alex had bought Lucas Moura, he would have done exactly the same thing. To understand you need to look at what happens in United's Academy and what Rene Meulensteen brings to the table.

While Rene is now first-team coach, he was originally brought in as technical skills coach. He has a Dutch background and upbringing. What Ferguson wanted was a resource that could instill the way young Dutch players can play, together with all-round technical skill in every department.

So United signed Rafael and Fabio who, although they were playing at wing-back, were natural attacking players. But Rene taught them to tackle better and to stay on their feet. Rafael has also become an excellent header of the ball for his height.

And Chicharito has been taught to drop back into midfield to help out as needed and get hold of the ball as appropriate; he has become better at dribbling; he is found out wide more often and can cross when needed; he can even tackle; and his all-round goal-scoring ability has improved.

Remember, Sir Alex took a rangy, skinny genius with the ball and turned him into Cristiano Ronaldo, one of the finest all-round athletes and arguably the greatest footballer in the world.

So if you look at the United Academy approach, defenders learn to attack; attackers learn to tackle and defend; youngsters are tried out in all the positions on the field; and they come through as all-rounders able to fit with United's highly adaptive style and tactics, which can change spontaneously and as needed during a match.

The solution

The solution to how United can replace Paul Scholes and become truly great, therefore, is in fact not to replace him with a Scholes clone. There isn't one. It's not what is needed. The game and United have moved on.

It must be clear by now that United are not, never will be and don't want to become, a Barcelona. Of course they want Barcelona's success.

No, correct that.

They want United's success, as good as it's ever been. Sir Alex is in the process of creating the next truly great team and to do so he needs one last piece of the jigsaw.

So how can he do that? Probably with very different alternatives.

It's not Michael Carrick. He is the pivotal player for the time being and his form this season has been outstanding, possibly leading to him being United's player of the year now Van Persie's form has gone off.

It could be Tom Cleverley. Sir Bobby Charlton was also one of his role models. Cleverley was tried as a left-back and an attacker in the academy before he settled into his midfield berth.

But he's not like Paul Scholes. Now coming back to the levels he was at early last season before his injury troubles, he is a dynamic midfielder who is just as comfortable alongside Carrick as he is bursting forward, linking up with the attackers and even scoring goals.

We have described him before as the "glue" in United's midfield. Together with Carrick they are Sir Alex's first-choice midfield pairing right now.

And you could say that Xavi and Iniesta are Barcelona's "glue." Joe Allen was Swansea's "glue" in a team where there were no household names, but they were a highly effective unit.

If Manchester United are going to go outside to find the one player to complete the jigsaw and make them truly great again, then it is not a Joe Allen. Nor is it a Roy Keane. The game has moved on.

We have frequently mentioned Kevin Strootman as a possible United signing. Most people cite his "box-to-box" and tackling abilities. He could become the key player if he was signed, but again Sir Alex and Rene would work on him and add other dimensions to his game.

On the other hand, Christian Eriksen could very definitely become the answer. He has grown up in Dutch football; he is technically excellent; he has Carrick's calmness; and he fits the mould of recent signings like Kagawa and Van Persie as being highly intelligent in both a footballing and a general sense.

But the one player who does tick all the boxes is surely Luka Modric.

God knows Sir Alex has lauded and coveted him.

Of course he is not the new Paul Scholes, but he can be every bit as effective and perfectly fits United's new style and adaptability.

Does he have the capability to help United become truly great? You bet. Just look at how he transformed Real Madrid after he came on last Tuesday.

It is irrelevant that United only had 10 men on the pitch. It was that ability to inspire, have an immediate impact and transform a Madrid side that looked like they had forgotten how to score that exactly fits what Sir Alex wants.

And whereas while he was at Tottenham there was absolutely no chance of Daniel Levy letting him join United, there is surely every possibility that Sir Alex could get him from Real Madrid and probably for little more than £30 million.

Indeed if the United "money men," whether inside the club or at Nike or Chevrolet, want to complete the package of true greatness and marketability, then Ronaldo and Modric from Real Madrid would do it.

But if it's only Modric that will do nicely.

For the future and inside United's ranks going forward, the successor to Luka Modric could be Nick Powell, Adnan Januzaj, Andreas Pereira or Ben Pearson.