The 43-year-old Testaverde aggravated a right Achilles tendon injury in the first half of Carolina's loss to Indianapolis. He sat out the second half and has been receiving extensive treatment the past three days. Testaverde was seen riding to and from the practice field Wednesday in a golf cart.
Carr, who missed the Panthers' win over Arizona, replaced Testaverde despite still recovering from compression fractures in his lower back. Saying he was only at 80 percent, Carr threw for 103 yards, but the Panthers were outscored 21-0 in the second half of the 31-7 loss.
"He was well enough to play last week. There aren't a lot of players out there that are 100 percent at this stage of the season," coach John Fox said. "He looked sharp in practice today. He had a good day of preparation both in the classroom and out on the field."
Carr said he felt better than expected and was able to throw more deep balls. He acknowledged he was limited against the Colts.
"Just not being able to let go of a ball, let one rip. I actually was able to do that a couple times today with minimal pain," Carr said. "So if we can keep it going in that direction, it'll be all right."
Carr became the No. 1 QB after Jake Delhomme was lost for the season in Week 3 with a right elbow injury that required ligament replacement surgery.
With Testaverde's status uncertain -- Fox gave no update Wednesday -- undrafted rookie Matt Moore could serve as Carr's backup. Moore, who has played briefly in two games, was signed after projected third-string QB Brett Basanez was lost to a season-ending wrist injury late in the preseason.
"Really the first part of this season has been a little strange for the Panthers and for me," Carr said. "It's just been a wild deal as far as the quarterback situation. We just need to settle in and get into a routine of having the same thing week to week to week. That's going to make our team a lot better."
Dendy was released by Green Bay before the start of the season.