This is obviously speculative, but unless Cleverley develops a fairly similar skill-set to that of, say, David Beckham, I genuinely can't see how he can develop and remain as a wide player, particularly as the skill-set that he currently has is ideally suited to the central areas of the field.
I'm open to ideas in this regard, and it is certainly possible that he may further develop many of skills that allowed Beckham to remain as a wide player throughout his career, but Beckham needed to be one of the best exponents in world football at the things that he did well to remain in that position. Had he not been quite so good at those things, he would obviously not have been such a potent weapon from those areas of the pitch, and that may have persuaded at least one of his managers that he was better suited being used slightly inside.
It also depends on what the manager wants from the players in that position. Players that are employed in the attacking positions largely dictate what kind of team you are going to be, and also dictate, to some extent, at least, the kinds of players that are needed in the other forward positions. If you have wide players, for example, whose main asset is the early ball in to the box, that will largely dictate what kind of strikers you can also employ. It's not an exact science by any means, and most strikers are almost by necessity able to score goals in a variety of ways, but it's certainly true that not all players are suited to playing alongside each other, and most managers have a philosophy which, along with the demands of the game at a particular time, somewhat dictates the kinds of teams that can be built.
I don't believe that we will truly know what kind of player Tom Cleverley is likely to become for at least another two or three years, firstly, because that's when he will begin to mature as a player, and secondly, because he is likely to be used in the wide positions in the early part of his career, anyway, even if he does eventually become a central player. As we saw with Darren Fletcher, it's sometimes easier to give young players time on the field in areas where mistakes are less likely to have a major impact on the team. Center-backs are often played at full-back in the early part of their career for precisely this reason.
As to whether Cleverley should be sent out on loan, I would say that he should, as long as the manager can be fairly certain that he will be a regular starter, which is not always easy to ascertain. The most that you could probably guarantee if he remained at United is perhaps starts in the Carling Cup and the early rounds of the FA Cup, and the odd appearance from the bench in games that are all but over in the Premier League and Champions League group stages. There is obviously scope for much more than that, but it is dependent on a number of factors that are, at this moment, unknowable.
What if the team starts the season poorly and they are struggling to beat any teams by more than one goal? Is that really the right circumstance in which to start a young player? Obviously, if he goes out on loan to a bottom half Premier League side those are more than likely going to be the circumstances that he would find himself in, anyway. But that's to be expected, which is very different to the same thing happening at a club that is supposed to be challenging for the title.
If the observation that, on average, most players don't begin to make a genuine and consistent impact until they reach the age of ~22 is correct, it would be advisable to send him on loan to a Premier League side in the hope that he gets at least 15-20 starts, and at least begins to normalize his game to demands of the Premier League and to iron out some of the mistakes that players of that age inevitably make. The fact that he has a much better chance of appearing against teams in the top half of the Premier league while on loan is also an attractive proposition, because it is in those games that both the player and the staff at United will learn the most.
