HOUSTON -- Offensive lineman Rob Turner, carted off the field in the first quarter of Monday night's loss with an ankle injury, will have an MRI exam Tuesday to determine the severity.

Turner, who started at center for the injured Nick Mangold, is perhaps the most valuable backup on the team. He plays center and guard, can line up as a tight end in "jumbo" packages, can play defensive line in the goal-line defense and is a wedge blocker on kickoff returns.

Losing Turner for an extended period "would be a concern," Rex Ryan said. "Hopefully, it's not too bad of an injury."

Just the other day, Ryan remarked that the Jets' offensive line, from one to seven, is the best in the league. Suddenly, their depth is precarious. Behind Turner, the next backup in the pecking order is Vlad Ducasse (two sacks), who struggled mightily as right guard, right tackle and left guard.

Ryan defended his second-year lineman.

"He made some mistakes, no question ... but this kid is getting better," he said.

With Turner and Mangold, who is expected back this week, the Jets had to use third-stringer Robby Felix at center. Also remember, they didn't have RG Brandon Moore (hip). When was the last time the Jets' vaunted offensive line looked this vulnerable?

"Our offensive line back been a strength for a long time," Ryan said. "I think we'll feel better when Brandon and Mangold get back out there."

If the Jets need to sign a veteran center, they will find slim pickings in the free-agent market. The most recognizable name is former Giants C Shaun O'Hara, cut recently by Big Blue.

In other injury news, backup QB Mark Brunell is nursing a sore left pinky -- his throwing hand. He jammed it the other day while taking a snap in practice. It's not a fracture and "it's nothing major," according to Ryan, who described it as a dislocation. Brunell said he expects to be back in a few days. He didn't play, as expected, and was seen before the game with a wrap on his pinky.

Backup RB Joe McKnight suffered a head injury, a possible concussion, and left the game.