The receiver ended the Panthers' final full practice of camp Tuesday not only working with the first team, but also returning punts.

Because of injuries to Steve Smith, D.J. Hackett, Ryne Robinson and Dwayne Jarrett, and Smith's impending two-game suspension to start the regular season, Carter has gone from seemingly having almost no chance to make the regular-season roster to being run ragged at practice in multiple positions.

"Oh wow. Going from outside to inside, to slot to other side, I've been playing all four positions at the wide receiver spot," Carter said Tuesday. "Then going to special teams, you get drained real quick."

Not that he's complaining. Not after playing in one NFL game in two years since leaving Texas A&M and spending most of last season on Carolina's practice squad.

"I'm a very optimistic person. I always feel something positive is going to happen," Carter said. "I feel like I work hard. I feel like the coaches know my work ethic. I feel like they know I'm going to do whatever I can to try to make plays. When the ball goes up, I feel it's my ball."

The 6-foot Carter was one of the early standouts in practice, making impressive catches while working with the backups. Then Carter was thrust into returning punts after Robinson sprained his left knee early in camp. As the other receivers were injured, Carter was switched to several positions.

When the Panthers first lined up with three receivers in Saturday's preseason opener, Carter joined Smith and Muhammad. Carter has worked with the starters the past two days while Smith recovers from a concussion.

"Jason Carter has been one of those pleasant surprises, and you've got to have a couple of those unexpected pleasant surprises," Muhammad said. "He's playing well. He had great offseason workouts and he's carried that right into training camp."

Carter caught three passes for 32 yards against Indianapolis, and returned four punts for minus-1 yard. Carter said he should have called for fair catches on at least two punts where he was immediately drilled to the turf.

"I guess I should have thrown my hand up for a fair catch, but I wanted a chance to return it," Carter said. "I didn't really care about getting hit or anything like that because it's football. I should have thrown my hand up and made the smart decision, but you live and you learn."

Carter has been shaky returning punts, which he did briefly while he split time on Minnesota's active roster and practice squad as an undrafted rookie in 2006. Carter caught an earful from special teams coach Danny Crossman on Monday when he dropped two punts in practice.

"Not doing it for almost a year and a half, I'm kind of rusty back there," Carter said. "But once I get the ball in my hands I feel like I can make plays."

Learning new positions is nothing new for Carter, who began his college career as a quarterback. He moved to receiver as a sophomore and accumulated 1,270 all-purpose yards as a senior.

Carter could start Thursday's preseason game at Philadelphia. And with Smith to miss the first two regular-season games for punching teammate Ken Lucas in practice, the Panthers could decide to carry an extra receiver on the 53-man roster.

Either way, Carter is in the mix to be in uniform opening day in San Diego. Not bad for a guy who came into camp as the No. 6 receiver.

"I tell you man, he's doing a lot of good things," Muhammad said. "If all else fails and you're making plays, you can accept some of the other things that are not going so well, as far as learning the nuances of the position. From what I see, he's definitely on the right track and he's doing well. He's a great surprise for us."