CHARLOTTE, N.C. -- Cam Newton will start Carolina's preseason game against the Cincinnati Bengals.

Panthers coach Ron Rivera said Sunday that Newton will play the first three quarters on Thursday night against the Bengals, but that doesn't mean the rookie quarterback will be the starter in the Sept. 11 season opener.

"It will give us an opportunity to see how he'll handle the whole game experience and we'll go from there," said Rivera, who hedged on anything past then.

"It makes him the starter for Thursday. We are still in the evaluation process after having gone through a game where we did some good things, but not enough good things."

Newton started and played the entire first half of Friday night's 20-10 loss to Miami. He finished 7 of 14 for 66 yards. Newton also ran four times for 18 yards.

Jimmy Clausen started the second half against the Dolphins and went 9 for 15 for 69 yards.

Rivera said after watching film it became apparent that Newton, the No. 1 pick in the April draft, has improved his mechanics since training camp opened.

"It didn't show, obviously, but the biggest thing is he was making good decisions and that's probably the biggest thing," Rivera said. "Anytime you see a guy make the decisions that you're supposed to make, the next part of it is delivering the ball on time and hitting the receivers in stride and stuff like that."

Rivera had previously indicated he'd name his regular-season starter this week, but said Sunday he's not ready.

"I think the big thing we have to do is continue to evaluate the situation and the circumstances," Rivera said. "I think we've only gone through about three-and-a-half or four weeks of training camp, and to rush to a decision would be kind of absurd. We want to see how he handles this whole game-week situation."

Also Sunday, Carolina defensive end Greg Hardy practiced for the first time this preseason. He had been out with injuries sustained in a July motorcycle accident.

Rivera said Hardy is an "every-down defensive end,"

"He will work himself back into shape, and when he's ready to go he'll be one of our starting defensive ends," Rivera said. "I didn't recognize him, I'm so used to seeing him in street clothes. He worked hard and intermingled with his group and he had an opportunity to get out there with the first (team) and take some snaps.

"We were excited to have him back on the football field."

Chris Gamble also practiced Sunday, leaving middle linebacker Jon Beason as the only defensive starter still out.