The Daily Mail is reporting that the 20-time English champions are eager to sign a new centre-half to help Mourinho solidify his defene ahead of the new Premier League campaign.
Victor Lindelof struggled to impress during his debut season at Old Trafford, while Eric Bailly, Phil Jones and Chris Smalling have struggle with consistency.
The same article states that Manchester United will also look to sign a forward should France star Anthony Martial leave Old Trafford before the close of the transfer window.
The 22-year-old has been linked with a potential switch to Chelsea FC and Tottenham Hotspur this summer, as well as Bundesliga giants Bayern Munich and Borussia Dortmund.
Manchester United finished in second place in the Premier League table last season but ended up a staggering 19 points adrift of runaway champions Manchester City.
The Red Devils lost 1-0 to Chelsea FC in the FA Cup final at Wembley after Jones brought down Eden Hazard and resulted in the Belgian forward scoring the winner from the penalty spot.
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