Man United don't have a midfield apart from Carrick, man. The White Djemba-Djemba is more or less first choice. Of course he could play for them, far worse players have played key roles for Man United sides over the years.
Gonna be mint when we flog him to somebody, everybody decides he wasn't that good anyway (despite moving to much bigger/wealthier club) and we inevitably fail to replace him, have an even smaller and less talented squad next season and we're still stuck with the cockend of a manager. What an exciting future for the club.