Manchester United striker Marcus Rashford is facing at least six weeks on the sidelines with a stress fracture of the back, manager Ole Gunnar Solskjaer has told Sky Sports.
"He's suffered a bad injury, it's a stress fracture," Solskjaer said following Sunday's defeat to Liverpool.
"It happened against Wolverhampton and it is not something that has happened before. I'm looking at Marcus to be out for a while. He won't be back, I'm not a doctor so I don't know exactly, but we are looking at several weeks and then some rehab after that probably.
"We've had many injuries to big players this season, it's just an unfortunate position that we are in. The window is open and it might be that we look at something for the short term.
"We are not desperately looking. We are looking at numbers and if the right one is there for us then something might be possible."
United missed Rashford as they lost 2-0 to their long-time rivals, goals from Virgil van Dijk and Mo Salah enough for Liverpool to extend their lead at the top of the table to 16 points.
Solskjaer added: "Of course you're never happy to lose a game. The first goal was disappointing, to concede from a set piece. I then thought we weathered the storm really well and then put them under pressure, I thought they looked nervy.
"There were times we took the game to them and created chances, big chances. We then send everyone up to get the equaliser and they get the goal.
"They stamped their authority on the game, they lead the league deservedly and they are the most direct team in the league. They put you under pressure and you have to concentrate at the back. It was a much better performance than a year ago here."
Asked if the title was now won, Van Dijk told Sky Sports: "No. I think everyone wants us to say something about it but we won't. In the squad we can not, and we won't. It is one game at a time."
Jordan Henderson added: "They played well at times. One nil is a dangerous scoreline and I feel as though we should have killed the game off earlier with the chances we had, but we kept going and defended well.
"There's always expectation to win here, there has been since I came to the club, and that will never change. We've got to stay hungry and keep wanting more and keep wanting to improve - and we know we can improve. It's about keeping going until the end of the season."