Leeds forward Jamie Jones-Buchanan is expected to miss the rest of the season - including the Rhinos' latest trip to Wembley - with a snapped knee tendon.
The 33-year-old forward was carried off on a stretcher during Friday's 24-14 Challenge Cup semi-final win over St Helens at the Halliwell Jones Stadium.
"We are talking months rather than weeks," said coach Brian McDermott.
"He's snapped a tendon in his patella around the outside of his knee. You really do feel for him."
|Jamie Jones-Buchanan has spent his whole career with Leeds Rhinos, in which he has won six Grand Finals and a Challenge Cup winner's medal. He is contracted with the Rhinos until the end of the 2016 season.|
Leeds lost Jones-Buchanan for three months last season with a biceps injury, although he did recover in time to help the Rhinos beat Castleford 23-10 at Wembley - their first Challenge Cup triumph for 15 years.
"He's gone through the mill over the last couple of years," added McDermott.
"You just wonder, if he didn't play the game like he did, which is 100 miles an hour and tipping his guts into everything, whether he would get injured.
"He landed funny on his knee but the team needed that type of carry. It's ironic that he injured himself doing what he does best for the team, which is carrying the ball forward at a million miles an hour."
Leeds will play Hull KR in an all-Yorkshire final on 29 August, following Rovers' surprise 26-18 win over Warrington at Headingley on Saturday.