Updated

Just three days after getting knocked out of Carolina's season opening loss with a concussion, Panthers quarterback Matt Moore practiced and expressed confidence he'll play Sunday against Tampa Bay.

If Moore passes additional cognitive tests and is cleared by doctors later this week, coach John Fox will give Moore a chance to atone for a poor season debut and delay rookie Jimmy Clausen's first NFL start.

"I felt good today," said Moore, who was listed as being limited in Carolina's workout Wednesday. "We'll wait and see what the doctors say or whatever, but I felt really good."

It was a big improvement from Sunday, when Moore acknowledged it took a second jarring hit to realize he had suffered a concussion on the previous drive when his head banged against the turf. Moore, who threw three end zone interceptions and lost a fumble, was helped off the field after Osi Umenyiora sacked him late in the fourth quarter of the New York Giants' 31-18 win.

"I think the hit from behind really triggered something or made me realize something is not right," Moore said.

Then came the nausea followed by an ambulance trip to the hospital for evaluation. But when asked if it would be accurate to describe it as a "mild" concussion, Moore replied that it was "nothing crazy."

Just being allowed on the field proved Moore — and reserve receiver Charly Martin, who also returned to practice after a concussion Sunday — showed progress.

Under the NFL's new, stricter rules regarding concussions, Moore had to pass a series of tests before he could practice. Philadelphia quarterback Kevin Kolb, who also sustained a concussion Sunday, didn't pass those tests and wasn't allowed to practice on Wednesday.

"Concussions are not created equal," said Dr. Thom Mayer, medical director for the NFL Players Association. "A player has to have a normal neurological exam at rest and after exercise. He has to have normal neuropsychological testing. He has to be cleared by both the team's physician and the independent neurological consultant. Only after all those things can the player go back and play."

Mayer added he expects the Panthers to "monitor him very carefully" and do neuropsychological testing again later this week. If Moore has any setbacks, Clausen would take over. He threw two incomplete passes in relief of Moore in his NFL debut Sunday.

"I think I'm ready to go if my name gets called," Clausen said. "And I have to be ready to go, no questions asked."

Moore apparently did OK in practice on Wednesday. Fox said he "looked just like normal Matt," and running back DeAngelo Williams called him "a warrior."

But that warrior mentality is why the NFL is more cautious with concussions, which occur when a blow to the head causes the brain to shake inside the skull. There have been concerns about long-term affects such as memory loss, depression and dementia for players who suffer multiple concussions.

Moore said he had a concussion once before in his junior year of high school.

"Medical staff, coaches and the media are more educated and receptive to the detection, evaluation and treatment of concussions," said Dr. Adam Shunk, a neuropsychologist at St. Vincent Sports Performance Center in Indianapolis. "Previously these athletes may have not received treatment and might have unsafely returned to play before they were ready."

If Moore is cleared, he will start, Fox repeated on Wednesday. Fox isn't ready to turn to Clausen, the former Notre Dame standout, even after Moore made several poor decisions and posted just a 32.6 passer rating against the Giants.

"Needs to be a little better," Moore said of his play. "But we've got another week."

Notes: DE Tyler Brayton (ankle), WR Brandon LaFell (hamstring), RT Jeff Otah (knee) and DT Louis Leonard (elbow) missed practice. ... RB Tyrell Sutton (shoulder) and LB Jordan Senn (ankle) practiced on a limited basis after missing Sunday's game. ... Rhys Lloyd was given the No. 8 in his second stint as Carolina's kickoff specialist. He was signed Tuesday. "It's like I never left," Lloyd said. "There's obviously a lot of new faces in the locker room, but it's good to be back."