Burnley boss Vincent Kompany admits Luca Koleosho has been hit by a knee injury.
The winger is facing months on the sidelines.
Kompany said: "It's bad news for us - Luca will be out for a while. We'll do everything we can that he can get back healthy and ready to go again. In a collision he did something to his knees. I'd like to think he'll play this season but it may be towards the end of the season.
"Past the fact that it's a blow for a young player, I still think it's for someone else to step up and wear the shirt in the way Luca has done. With, him being young, in these moments, if you keep calm, you can get better and stronger. I have no doubt he'll come back stronger."
On forward Lyle Foster, who was put in the care of specialists last month after the recurrence of a mental health issue, the manager said: "Lyle is making good progress, we've spoken about two names where the details, margins count, it could be better but as well we will recover both players and when they're ready to go again we'll benefit from them being Burnley players.
"He's [Lyle Foster] getting good care, he's in a better place than four weeks ago, I'm hopeful it won't be too long before he can come help out again."
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