Manchester United tried to sign Mats Hummels of Borussia Dortmund and Sporting Lisbon's William Carvalho in the frantic final week of the window, sources have told ESPN FC.

United spent more than 150 million pounds, which was a record for any club in a single window. Despite that, they were prepared to spend even more, as manager Louis van Gaal still wanted to bring in a commanding centre-back and midfielder.

The initial top target as regards the latter was Juventus' Arturo Vidal, but doubts over the condition of his knee meant the club were reluctant to spend a huge fee on a player who may have required an incentivised contract.

ESPN FC was also told that another early primary target was Hummels. United had made an enquiry about the Germany defender in June only to be firmly rebuffed by Dortmund, but the English side broached the possibility again when negotiations began over Shinji Kagawa's return to the Westfalenstadion.

United suggested Hummels could be exchanged for 20 million pounds and the Japanese midfielder, but Dortmund again rejected the idea and ultimately signed Kagawa for eight million euros.e