Mats Hummels (Borussia Dortmund)
One particularly fanciful link that has been made between United and a centre back this summer is that of Borussia Dortmund centre back Mats Hummels, with the world class defender reportedly a target for van Gaal.
The German international is unlikely to want to move from a Dortmund team still capable of challenging in both the Bundesliga and the Champions League to a United team without the capability of offering European football until 2015/16, however.