Well he's no Luke Shaw, obviously. Maybe he hasn't been approached because Utd have made it pretty clear they'd rather make marquee signings for positions they're already competitive in than address the obvious deficiencies in their squad. Probably because it would involve being a bit more utilitarian and having to sign one or two "unknowns" like Vlaar, which as those RedCafe quotes show, will go down badly with a fanbase whose expectations have no bearing on the situation they find themselves in.
This is exactly why I think they haven't approached him. They know he is good enough but pride is stopping them from making the bid. If they get desperate they will swallow that pride and approach us IMO.
Hope not though.
You have to remember. This is a fan base that feel they can still win the league.