Thomas Davis tore the anterior cruciate ligament in his right knee for the second time in the past seven months, but the Carolina Panthers aren't giving up hope that the linebacker could return sometime this coming season, a source with knowledge of the situation told NFL Network insider Jason La Canfora.
The Panthers revealed the extent of Davis' injury Wednesday, one day after his knee buckled during a non-contact drill in a voluntary workout.
Davis had been making a remarkably speedy recovery after he first injured the ACL during a Nov. 8 game at New Orleans. He was clocked last month running the 40-yard dash in 4.47 seconds, making the Panthers believe he could return to the form that allowed him to collect 71 tackles, 1.5 sacks and two interceptions in seven games before he was hurt last season.
"Thomas is an explosive player," Panthers general manager Marty Hurney said. "He's a playmaker, a leader, great in our locker room, and he's someone everybody respects. 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 pass coverage. He immediately clutched his right knee before walking off the field.
An MRI Tuesday afternoon showed the tear, but Davis and his agent, Todd France, wanted to receive a second opinion from renowned surgeon James Andrews. The doctor confirmed the injury 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," France said of Davis. "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 that 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 Davis, 27, will be an unrestricted free agent next spring after the Panthers offered him just a one-year, $3.268 million tender as a restricted free agent this offseason. Davis signed the tender shortly after being injured Tuesday.
"He'll surely be 100 percent come free agency and all that," France said. "I don't think that's going to be an issue. The long-term deal will work itself out."
The Panthers have the option of placing Davis on the physically-unable-to-perform list once he fails his training-camp physical. That would allow the team to activate Davis later in the season.
But Davis' 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 in which Davis thrived 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 the Chicago Bears in the Chris Harris trade in April, James Anderson and Dan Connor are other possibilities.
The Associated Press contributed to this report.