The Uruguayan international has racked up 38 appearances for his country since his debut in 2007, and was a key player in his country's Copa America 2011 triumph. The 24-year-old is currently in his second loan spell at Italian side Juventus.
United have been a hive of defensive woes this season. Talisman Nemanja Vidic suffered a long-term injury early in the season and his teammates have struggled to keep strong in his absence. Particular criticism has been aimed at Jonny Evans, who fans believe should not be a first-team player, and Rio Ferdinand who has been deemed by some as past his peak.
Other minor injuries to players have unsettled United's back line, and communication has been a big issue among the defence.
Youngsters Phil Jones and Chris Smalling are not ready to take the reins of the club on their own yet, as they proved against Ajax in midweek, so an older and more established player could be a great addition to the back line.
Caceres is not the only centre-back to have been linked with the Red Devils in recent months. Mehdi Benatia of Udinese, Neven Subotic of Borussia Dortmund and Adil Rami of Valencia have also been linked to the Theatre of Dreams.
Despite being a natural centre-back, Caceres can play anywhere across the defence and his strengths include his passing and dribbling. He's also been known to get the odd goal—on his re-debut for Juventus earlier this month, he scored both goals in their Coppa Italia win over AC Milan. Check out the goals from that match here—be sure to keep an eye out for his fantastic off-the-ball run for his first and his cheeky shot from outside of the box for his second.
Caceres' price is said to be around £11 million, which wouldn't be too much of a stumbling block for either United or Spurs.
Would you like to see Man United sign Martin Caceres in the summer window? Do you think United need another defender? Get your views heard in the comments.