CB: Jose Gimenez (market value: £31.5 million)
Gimenez is a Uruguayan centre-back currently playing for Atletico Madrid. He was heavily linked with United before they moved to sign Lindelof from Benfica.
Gimenez is still only 22, and being more experienced than Lindelof, would have been a better signing. But Atletico managed to hold on to him amid interest from United, Arsenal and Juventus.
But this season, Simeone has mostly stuck to a centre-back pairing of Diego Godin and Stefan Savic, leaving Gimenez out in the cold with only six starts in La Liga. This may reignite Jose Mourinho's interest in the Uruguayan.
If a deal does happen, his market value is estimated at around £30 million, which would mean United would probably have to stump up at least £40 million to convince Atletico to depart with their player. Even at that price, Gimenez would be a great signing and an investment for the future.