Mats Hummels, Borussia Dortmund
With Ferdinand and Vidic heading off for pastures new, recruitment in central defence is a priority for van Gaal as question marks still remain over the capabilities of Phil Jones and Chris Smalling in the position.
In Hummels they would be able to acquire a centre-back who is considered to be among the best in the world currently and the German is still relatively young at 25-years-old.
Source: Goal.