Manchester United striker Robin van Persie could be out for more than two weeks with an ankle problem, says manager Louis van Gaal.
Van Persie, 31, fell awkwardly after putting over a cross in the defeat at Swansea on 21 February.
The Dutchman left the Liberty Stadium on crutches and wearing a protective cast on his right foot.
"I do not think it is very heavy but ankle problems can take a long time," said Van Gaal.
"It is not one or two weeks."
It means Van Persie will miss the forthcoming Premier League games with Sunderland and Newcastle, plus the FA Cup quarter-final with old club Arsenal at Old Trafford on 9 March.
Midfielder Michael Carrick is available after missing six games with a calf injury.
United have only lost one game when Carrick has started this season but Van Gaal said tomorrow's game might come too soon for the 33-year-old.
"He needs match rhythm," he said. "He only trained one time with the group."
'It's a rat race'
The defeat at Swansea dropped United to fourth place, with four points separating Arsenal in third and Tottenham in seventh.
"It is a rat race between five clubs," said Van Gaal. "Therefore you have to win your matches because the other clubs are winning their matches.
"We are not unhappy. I am pleased with the results, but not with a lot of the performances.
"If you told me at the start of the season I would be in the first four at the start of May, I would have signed for it.
"When I came here, that was my goal and we are still there. But, of course, it would be a big disappointment not to make it."