The 33-year-old snapped a knee tendon in Friday night’s semi-final victory over St Helens, and his season could be almost over.
“We are talking months rather than weeks,” said Rhinos coach Brian McDermott.
“He’s snapped a tendon in his patella around the outside of his knee. You really do feel for him.
“He’s gone through the mill over the last couple of years.
“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.”