Testaverde, who has not played since injuring his right Achilles' tendon in the loss to Indianapolis on Oct. 28, practiced without limitations, splitting time with undrafted rookie Matt Moore.
Carrm, who watched practice from the sideline, has yet to be cleared from the concussion he sustained late in Sunday's loss at Tennessee after a hit from defensive tackle Tony Brown. Carr was also sidelined last month with a back injury that forced the team to sign Testaverde, who turns 44 next week.
Fox gave no update on Carr's condition and refused to select a starter for Sunday's game against Atlanta.
The biggest concern has been at quarterback, where four quarterbacks have suffered five different injuries.
The Panthers lost original starter Jake Delhomme to a season-ending right elbow injury in Week 3. Projected third-string quarterback Brett Basanez was lost to a season-ending wrist injury late in the preseason.
After Basanez was placed on injured reserve, the Panthers signed Moore, who played at Oregon State and was one of Dallas' final cuts of the preseason. Moore, who has appeared briefly in three games because of injuries, is 3-of-7 for 79 yards and one interception.
But with Moore's inexperience, it appears Testaverde would start Sunday against Atlanta if he's healthy and Carr can't go.
"He hasn't been here that long," Fox said of Moore. "He's definitely made progress. A lot of this game is mental, and it's just a matter of him getting acclimated to the offense."
Testaverde might start ahead of Carr even if both are healthy. Carr, signed as a free agent in the offseason after being a five-year starter in Houston, has struggled. His average of 4.74 yards per attempt is the lowest in the NFL and he's appeared indecisive at times. Carr was sacked seven times in the loss to the Titans, and Fox acknowledged he often held the ball too long.
Carr, who has three touchdowns and three interceptions, has also had trouble getting Smith the ball. Smith has been held to three catches for 15 yards in the past six quarters Carr played. Smith had two 100-yard receiving games with Delhomme and one when Testaverde started in the win at Arizona.
Former UCLA quarterback Drew Olson, signed to the practice squad Tuesday, worked with the scout team Wednesday. Olson, who was cut by Baltimore in August, was brought in to allow the Panthers to have enough quarterbacks to practice.
Copyright 2007 by The Associated Press