Carolina Panthers coach Ron Rivera said Monday the team will move free safety Sherrod Martin to the injured reserve after the fourth-year player tore his ACL and MCL against the Kansas City Chiefs in the second quarter Sunday.

Also, wide receiver Brandon LaFell had a walking boot on his right foot after getting an MRI on Monday morning. The extent of his injury has yet to be disclosed.

Martin was injured on the first play after the two-minute warning in the second quarter of the Panthers’ 27-21 loss on Sunday. He had played seven snaps before the injury.

Rivera praised Martin, who had seen his role increase at the expense of starter Haruki Nakamura, for his improved play this season.

“We've been able to refocus him on the things he needs to improve on, tackling being one of them,” Rivera said. “He's really done a nice job. His ability seemed to start to show. He put himself last week in Philadelphia in position to make plays. He got himself in position to make plays (at Kansas City). That's how he got hurt, trying to make a play.”

Now, Martin will enter the offseason with as a first-time free agent with surgically repaired right knee.

“I'd definitely love to be here (with the Panthers in 2013),” Martin said. “But for me to be able to get back on the field, period, I've got to get healthy. So it's just all about one day at a time and just focus on getting back.”

Rivera said the team could move a player up from the practice squad to fill Martin’s position, but he did not rule out signing a free agent.

LaFell injured his right foot in the third quarter, on a play when quarterback Cam Newton threw to LaFell for what would have been about a 40-yard reception inside the Chiefs’ 10. LaFell missed the catch, saying Monday he took his eyes off the ball, and was taken to the ground by the Chiefs’ Javier Arenas.

Should LaFell not be able to go, Louis Murphy would be the Panthers’ No. 2 wide receiver.

“The last few weeks in particular (Murphy has) made some big plays for us,” offensive coordinator Rob Chudzinski said. “He’s a guy that works extremely hard, he’s got a great attitude about things.

“He’s getting some opportunities and when you get opportunities you have to make plays, and he’s been doing that the last couple weeks especially.”

COSTLY ERRORS: The Panthers committed seven penalties Sunday, including three defensive penalties that extended Kansas City drives.

An illegal hands to the face call on Greg Hardy gave the Chiefs a first down in the second quarter; Charles Johnson gave Kansas City another with a neutral zone infraction during a nearly 10-minute drive for a touchdown.

In the fourth quarter, a personal foul on Josh Thomas for pushing a Chief well after the whistle helped move Kansas City into field goal range and make the score 27-21.

Rivera said he would discipline Thomas internally.

Defensive coordinator Sean McDermott said the defense couldn’t match Kansas City’s intensity.

“This is an emotional, physical game and you have to play it that way,” McDermott said. “ Within that, you’ve got to stay disciplined, and I’m referencing the penalties. Totally unacceptable. Again, I take responsibility for it. That will not happen going forward.”

STEWART IMPROVING: Running back Jonathan Stewart, who missed Sunday's game with a high ankle sprain, said he is improving, but gave no timetable for his return. Starting in his first game in nearly two months, DeAngelo Williams carried the ball 12 times for 67 yards.

DISAPPOINTED DAWG: Panthers linebacker Thomas Davis said he thought Georgia mishandled the final seconds of its 32-28 loss to Alabama in Saturday's SEC Championship Game.

With Georgia at Alabama's 7 with 15 seconds left and out of timeouts, coach Mark Richt did not call for quarterback Aaron Murray to spike the ball and stop the clock.

Instead, Murray's tipped pass was caught by Chris Conley, who was tackled around the 5, and time expired.

“I feel like we should have done a better job of clock management,” said Davis, an all-SEC safety at Georgia. “I think if we spike the ball after we get that last first down, then we have at least two shots at the end zone.

“That can all be said now, but if he goes out and throws a touchdown pass on that play then it's different.”