Newton underwent X-rays as a precaution, and coach Ron Rivera said they came back negative.
After escaping pressure, Newton scrambled for 7 yards on first-and-10 before taking a shot to the back from Patriots linebacker Jamie Collins. Collins' knee appeared to drive into Newton's back as he delivered the big hit.
"He got the wind knocked out of him," Rivera said. "He's sore."
Newton tried to lead the team's huddle for the next play but stayed down on one knee, leading to an injury timeout called by the referees. Backup quarterback Derek Anderson came in for one snap while Newton was examined by the medical staff before returning to the field. After the half, Newton led the offense for its first series of the third quarter, but he left for the locker room and remained there for the rest of the game.
"They took X-rays just to make sure those are negative," Rivera said. "But again, we brought him back in, we got him checked. X-rays were on the contusion to the back.
"And once he was in, we kept him in and checked his ankle."
Newton, who had surgery on his left ankle during the offseason, did not hurt his ankle and the check was precautionary, Rivera said. Despite citing Newton's soreness after taking the hit from Collins and being sacked three times, Rivera is confident Newton's back is fine.
"Yes, that is the initial plan but we will see how he is tomorrow," Rivera said about Newton's status for playing in the Panthers' final preseason game. "He's pretty sore. Once again, there is nothing there other than that he took a pretty good shot."
Newton was not available for comment after the game.