Reading's Jem Karacan is set for a lengthy spell on the sidelines after suffering a knee injury in Wednesday's 1-0 victory against Leeds United.
Karacan was stretchered off early in the game and boss Nigel Adkins says the prognosis does not look good for the 24-year-old midfielder.
"It's a serious injury," Adkins told BBC Radio Berkshire.
"We'll get a full diagnosis but we've got our suspicions and it's not looking good. It is a big blow."
Karacan, who came through Reading's youth system, has made seven appearances this season.
"He is one of our own, he has come through the system and we will look after him and he will come back stronger for it," added Adkins.
Adkins admitted it would be a huge loss for the club, with Karacan a key member of the squad.
"He has been outstanding in my eyes," he said.
"His range of passing, his enthusiasm, his work rate and desire - he is developing into the whole-round package of the modern midfielder.
"It is obviously a blow for the team, but more for Jem."