Ian Millward has said that Jake Webster could be out for the rest of the Super League season after injuring his shoulder and knee.
The Castleford Tigers centre will need a further scan to determine whether he requires surgery to repair the knee, which he injured while playing against Hull Kingston Rovers last month.
The club's coach told the Yorkshire Evening Post: "We will know more next week, but there's a big possibility he will be out for the season. He did his shoulder in the Hull KR game, but before that, at half time, he said his knee was a bit sore.
"His shoulder was all right a couple of days after the game, but we took him for a scan because his knee had swollen up. He may need a reconstruction. What we can't get over is the pain he must have been in, and he didn't complain.
"He's got to have another scan. There's the possibility of him playing for another month to see how he is, but he would need to have the operation down the track and that would be [him out for] six months."
Castleford face Huddersfield Giants this afternoon.