"It is the ankle, same as what was announced during the game," coach Eric Mangini said today. "We'll review it during the course of the week, like we do every injury situation."

Pennington injured the ankle when he was sacked during the third quarter of the Jets' 38-14 loss to the New England Patriots yesterday. He was scheduled for an MRI today, and Pennington wasn't available for comment at the team's practice facility.

Mangini, predictably tightlipped, said he wasn't yet aware of the severity of the injury, but planned to talk with head trainer John Mellody, director of orthopedics Dr. Ken Montgomery and team physician Dr. Elliot Pellman.

"They are all involved in the process," Mangini said. "I couldn't tell you 100 percent all of the different tests. What I can tell you, though, is it's very thorough and I'll meet with them later (Monday) and moving forward throughout the week."

A call by The Associated Press to Pennington's agent, Tom Condon, wasn't immediately returned, nor was an e-mail seeking comment.

If Pennington is sidelined for Sunday's game at Baltimore, Kellen Clemens would likely get the start. Clemens was impressive in the preseason, seizing the backup job while going 30-of-41 for 364 yards and four touchdowns.

"I prepare like I'm going to play, so if my number's called I'm in the best situation to help the team win," Clemens said.

With 10:06 left in the third quarter, Pennington was sacked by Jarvis Green, who appeared to roll on the quarterback's leg. Pennington was slow to get up and in obvious pain before standing up, then collapsing to the turf after taking a few steps and falling again. Pennington eventually hopped on his left leg to the sideline.

Pennington flung his helmet to the ground as he hopped to the bench and was immediately surrounded by team trainers. Clemens replaced him for one play as fans cheered the backup's entrance, with some suggesting that it was more derogatory toward Pennington.

"I would certainly hope not," Clemens said. "For anybody who knows Chad, there should be nothing but concern for him at that point."

Pennington returned for the next series with the ankle heavily taped and was clearly bothered by the injury as he limped to the line of scrimmage before each play. Despite the injury, he led the team on a scoring drive, capped by Laveranues Coles' 1-yard touchdown catch.

Pennington decided it wasn't worth risking further injury with the score 31-14 in the fourth quarter, and Clemens replaced him again. Pennington finished 16-of-21 for 167 yards and two touchdown passes to Coles, while Clemens was 5-of-10 for 35 yards.

Pennington's foot and ankle were heavily wrapped after the game, and he limped noticeably.

"It's a tough one," linebacker Jonathan Vilma said. "I don't know what happened to him. We'll see what happens and what the MRI says. We have Kellen backing him up and Kellen had a good training camp, a good preseason, so we'll play with who we've got."

Wide receiver Jerricho Cotchery said Pennington would be missed, but expects little dropoff on offense if Clemens has to start.