Louis van Gaal is also looking at another Dutch international, in the form of uncompromising defensive midfielder Nigel de Jong.
The AC Milan man is in a similar contractual situation to Vlaar and Man United are ready to offer £9m for the former Man City man, an offer that Filippo Inzaghi may accept as he continues to set about building a more youthful San Siro squad.
The 29 year old enforcer could provide valuable strength in the middle of the park and whilst new signing Daley Blind offers a similar steely ability arguably the former Ajax man is a more rounded performer.
De Jong would provide more strength in depth and could offer van Gaal a cost effective option to boost the quality of his squad.