MANCHESTER United have confirmed Juan Mata has had surgery on an injured groin.
In three seasons at the Red Devils, the 28-year-old Spaniard has never missed a game due to injury.
However, his season could now be over, according to Manchester Evening News.
Mata reportedly trained earlier in the week but complained his groin was sore and then had surgery on Thursday.
It comes at the worst possible time for manager Jose Mourinho with a packed fixture list with nine games in April alone, beginning with a Premier League game against West Brom.
Paul Pogba remains sidelined with injury, while defenders Chris Smalling and Phil Jones were forced out of the England squad with what Mourinho branded as "long-term injuries". There's also doubts over Marouane Fellaini's fitness.
With Ander Herrera and Zlatan Ibrahimovic serving the final match of their suspensions against West Brom, Mourinho has called up youngster Matthew Willock from the reserves to the first-team squad for the first time.