Samuel Luckhurst of the Manchester Evening News initially reported the news, stating Mata could be out for the season. The setback marks the first notable injury of Mata's United career.
Per James Ducker of the Daily Telegraph, the player expects to be back before the end of the campaign:
Mata emerged as one of United's top performers during the 2014-15 season after a shaky start under then-manager Louis van Gaal. Initially, it seemed as if the Spaniard was on his way out, but an injury to Angel Di Maria saw him return to the lineup in an unfamiliar role on the right-hand side of a front three.
The 28-year-old took full advantage with a number of excellent performances, and by the end of the season, he was once again playing regular minutes. The 2015-16 campaign was no different, and he featured in every Premier League match, per WhoScored.com.
Creativity was a major issue for United last season, and no midfielder provided more in that department than Mata. He also bagged a handful of important goals, including the equaliser in the FA Cup final win over Crystal Palace.
Under new boss Jose Mourinho, with whom he previously worked at Chelsea, Mata has been a regular contributor, and his absence could be a major blow. Per the report, Paul Pogba is also nursing a knock, meaning Matthew Willock was promoted to the first-team squad.
United are still battling for a top-four finish in the Premier League and the UEFA Europa League crown.