 Sinfield will miss the game with champions Bradford on Thursday |
Leeds could be without skipper Kevin Sinfield until the end of May after he was stretchered off with a leg injury in last weekend's victory over Hull. The 25-year-old loose forward had a scan on Monday but has not suffered any broken bones.
"There is certainly some ligament damage but it is not as bad as we first feared," said coach Tony Smith.
"I would think he would be out for something between four and six weeks but the scan will tell us more."
In Sinfield's absence, Jamie Peacock will stand in as captain, his first game in charge being against his old side Bradford.
"He is the Great Britain captain and has led from the front since he's been here," said Smith.
"He was highly regarded when he joined us and is even more so now."
Peacock said: "I'm obviously delighted to captain the team, although it's disappointing it's in such circumstances.
"It's something I enjoy doing, and I am looking forward to it."