Hull FC prop Nick Staveley is out for the rest of the season after rupturing his anterior cruciate ligament.
The 20-year-old suffered the knee injury in training last week, ahead of the Humberside derby.
Staveley has been a regular starter for the Airlie Birds in this campaign after making his breakthrough in 2023.
Head coach Tony Smith said: “We thought it would take two to six weeks, but it ended up that he’s damaged his ACL.
“It will be a nine-month recovery from the time of operation. It’s a lot more severe than first expected.
“It was from a rather innocuous occurrence in the team run last week. He was holding a tackle shield for another player to practice his tackle technique. He stumbled out of that in an awkward way. He didn’t think it was that bad at the time, but obviously it is.
“It’s a real blow for Nick. I feel for the young man. He was doing a good job for us, and he was starting to find his feet and get some regular game time in first grade. He’s taken the news very, very well and very positively. He won’t feel sorry for himself. He’s just got to get on with rehabilitating the best he can and get back as early as he can.”
Hull have struggled in Super League this season, winning just one of their six games, including a 34-10 beating by rivals Hull KR last weekend.
They face Huddersfield Giants on Saturday, when they will also be without experienced hooker Danny Houghton, who has a rib injury, and Jack Ashworth, who need surgery on a thumb problem.
