CHARLOTTE, N.C. (AP) -- Carolina weakside linebacker Thomas Davis has suffered a torn anterior cruciate ligament in his right knee for the second time in seven months, likely leaving the Panthers without one of their top defensive players for the 2010 season.
The Panthers revealed the extent of Davis' injury Wednesday, a day after his knee buckled in a non-contact drill in a voluntary workout. Davis had been making a remarkably speedy recovery after he was first injured Nov. 8 at New Orleans.
He was clocked last month running the 40-yard dash in 4.47 seconds, bringing hope he could return to the form that allowed him to collect 71 tackles, 1 1/2 sacks and two interceptions in seven games before he was hurt last season.
"Thomas is an explosive player. He's a playmaker, a leader, great in our locker room and he's someone everybody respects," Panthers general manager Marty Hurney said. "You always hate to lose somebody like that. You feel so bad for him because he really has worked so hard."
Davis wasn't wearing a knee brace Tuesday when he fell to the turf while backpedaling, similar to how he was injured the first time while dropping into coverage. He immediately clutched his right knee before walking off the field.
An MRI Tuesday afternoon showed the tear, but Davis and his agent wanted to get a second opinion from renown surgeon Dr. James Andrews. He confirmed the injury on Wednesday.
"If you know the kind of person and you know how hard he's been working to get back -- and basically almost at the finish line -- to have this happen is just so disappointing," agent Todd France said. "The only thing I can say is if there is one person that can rehab again and do the whole thing over, he's the one who has the right attitude and the work ethic to do it."
There were immediate questions if Davis returned from the first knee injury too soon, but Hurney and France insisted that wasn't the case.
"Obviously questions like that are asked when something like this happens, but it was the normal rehab procedure we've done with other people," Hurney said. "Even Thomas said he had felt very good about how the knee had felt."
France indicated Davis will undergo surgery either this weekend or sometime next week. It hasn't been determined if Andrews or the Panthers' team doctor will perform the procedure.
France said he was assured by Andrews that Davis can return to football. The injuries occurring so close together versus a couple of years apart prevents arthritis and other scar tissue concerns.
"He said there's no big picture issue, which is a great thing to hear," France said of Andrews.
That's significant because the 27-year-old Davis will be a free agent next spring after being offered just a one-year, $3.268 million tender as a restricted free agent this offseason.
"He'll surely be 100 percent come free agency and all that. I don't think that's going to be an issue," France said. "The long-term deal will work itself out."
The Panthers weren't immediately ruling out Davis for the entire 2010 season, as they'll have the option of placing him on the physically unable to perform list once he fails his training-camp physical. That would allow them to activate him late in the season.
But his injury leaves a void at one of the most important positions in defensive coordinator Ron Meeks' Cover-2 system. It calls for a speedy, athletic player to collect a big chunk of the tackles, a position Davis thrived in until he was hurt last season.
One option the Panthers haven't ruled out is moving Pro Bowl middle linebacker Jon Beason to Davis' spot. Jamar Williams, acquired from Chicago in the Chris Harris trade in April, James Anderson and Dan Connor are other possibilities.