United have not put a timeframe on Valencia's return but British media suggested he could be sidelined for six weeks. Matteo Darmian is expected to fill the vacant right back spot.
Valencia's injury is another blow to Jose Mourinho's side, who lost centre back Eric Bailly to a knee injury against Chelsea last week and is expected to miss up to two months of action.
United are eighth in the Premier League and trail leaders Manchester City by eight points after 10 games. They travel to face Swansea City in the league on Sunday before hosting Arsenal on Nov. 19.
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(Reporting by Ian Rodricks in Bengaluru; Editing by Peter Rutherford)
