Posted by ESPN.com's Tim Graham
Jenkins, whose greatness often goes overlooked by causal football observers, suffered a right knee injury in Sunday's 16-13 overtime loss to the Buffalo Bills.
Jenkins left in the second quarter and didn't return.
Jets head coach Rex Ryan didn't have specifics after the game but said, "I think it's probably severe." Sione Pouha replaced Jenkins. There was a noticeable drop-off.
Jenkins, perhaps the best nose tackle in the game, is the centerpiece of the Jets' 3-4 defense. He's an elite run-stopper who draws multiple blockers every play.
"I am very concerned about Jenkins," Jets linebacker Bart Scott said. "He is the anchor of our defense.
"It's huge. He is a great part of what we do. Someone is going to have to step up, and it can't be just one man. It's going to have to be a couple individuals that step up. We got our work cut out for us."
In other injury news, the Bills didn't have an update on quarterback Trent Edwards other than to confirm he suffered a concussion in the second quarter. Edwards also had a concussion last year, but it occurred one week before Buffalo's bye, and he didn't miss a game.
Bills safety Donte Whitner, who missed two games because of thumb surgery, left early with an ankle injury. Tight end Shawn Nelson had a concussion and defensive tackle Kyle Williams injured a shoulder.