Testaverde, signed on Wednesday, and undrafted rookie Matt Moore, signed just over a month ago, took all the snaps in practice for the banged-up Panthers. Coach John Fox wouldn't say which QB he'd use if Carr can't play Sunday.

Carr became Carolina's No. 1 quarterback when Jake Delhomme left a win over Atlanta on Sept. 23 with a right elbow injury. Delhomme has since decided to undergo season-ending surgery.

Carr was injured when his back bent ackwardly when he was sacked by Will Smith in the second quarter of Sunday's game at New Orleans.

He was carted into the locker room and replaced by Moore, who threw a 43-yard pass to Keary Colbert in a drive that produced a field goal.

Carr, after receiving treatment and taking several pain pills, returned in the second half against the Saints. He threw a touchdown pass to Steve Smith in Carolina's come-from-behind win.

But Carr has been able to do little since. He said Wednesday he's been receiving around-the-clock treatment. He watched Thursday's practice while wearing shorts and a T-shirt.

Fox wouldn't say whether he expected Carr to practice Friday.

"I was hopeful he would today, but he did not," Fox said. "We'll see what happens."

Testaverde went through his second practice with the Panthers on Thursday as he scrambles to learn the offense and get acclimated with Smith, Carolina's top receiver.

Testaverde, who turns 44 next month, was cut by New England in the preseason, Entering his 21st NFL season, Testaverde has impressed his new teammates with his arm strength and how quickly he's picked up the offense.

"He's got some familiarity with the system we've run and the coaches we have here," Fox said. "Hopefully he's a quick study. I think he is and he's shown that ability just in the last two days."

Moore, who played at Oregon State, was signed in September after being one of Dallas' final cuts before the regular season. It's uncertain how much confidence the coaching staff has in him to start.