Raphael Varane and Jonny Evans only have deals at Old Trafford until the end of June, while there remains speculation surrounding the future of Victor Lindelof and Harry Maguire.
Lisandro Martinez's ongoing injury problems will also be concerning for the Red Devils, with the Argentina international facing another month on the sidelines due to a calf problem.
Everton's Jarrad Branthwaite is thought to be the club's leading centre-back target, but the Englishman could potentially be priced out of a move to Old Trafford during the summer market.
According to the Daily Mail, Man United have been in touch with both Barcelona and Boca Juniors to ask about potential deals for Faye and Anselmino.
Man United allegedly scouting FayeMan United are believed to have been scouting Faye of late, with the 19-year-old making a strong impression for Barcelona B this season, following a switch from NK Kustosija last summer.
Faye has scored four times in 25 league appearances for Barcelona's second team this season, but he is yet to make his first-team debut for the Catalan outfit.
The Senegal international has been on the bench for two of Barcelona's last three league matches against Mallorca and Las Palmas, though, and he scored on his first cap for his country last month.
Barcelona would allegedly be willing to listen to offers of around £25m for Faye this summer due to their financial problems, and Man United are said to have a firm interest.
However, Bayer Leverkusen and Inter Milan are also believed to be competing for the youngster, who
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