Wayne Rooney is set to miss Manchester United's match against Middlesbrough this weekend after Jose Mourinho confirmed a muscle injury had kept him out of the Boxing Day win over Sunderland.
The England captain was sidelined for United's 3-1 triumph over ex-boss David Moyes' Black Cats at Old Trafford, where goals from Daley Blind, Zlatan Ibrahimovic and Henrikh Mkhitaryan made it four Premier League victories in a row.
And manager Mourinho conceded it was unlikely the 31-year-old - who is one shy of equalling Bobby Charlton's all-time record of 249 goals for United - would be fit to face Boro on Saturday.
"Honestly, I don't think so. I hope so," said the Portuguese. "I would like to have him, he's always a player I would like to have, but I have my doubts. Let's see the evolution.
"It's a strange muscle, a big muscle surrounded by others and you can have an injury there, but still be able to move well.
"He was not feeling very confident. It's not a big day [injury], but, in four days, I have my doubts."
Rooney has three goals in 22 appearances for United this season, with his solitary Premier League strike coming on the opening day of the season against Bournemouth.