"He's been struggling a bit," Fox said of the decision, indicating that he also replaced Gamble for a series last week against Baltimore.
Gamble played in the team's nickel package, but did not play at all in the base defense. Fox made it clear Gamble was not injured, although he did miss practice earlier this week for what was described as "personal" reasons.
Fox refused to elaborate on why he benched Gamble except to say, "It's a competitive league and a competitive position."
Gamble left the visitor's locker room before reporters were allowed in.
Munnerlyn didn't do anything to lose the job.
In fact, he may have cemented a starting role for next week against the Seattle Seahawks and possibly beyond when he intercepted a Jake Delhomme pass and returned it 37 yards for a touchdown, Carolina's first defensive score since DE Julius Peppers picked off Arizona QB Kurt Warner in Week 7 of last year.
Munnerlyn said he was told earlier in the week he would start if he could recover from a shoulder injury he suffered against Baltimore. Munnerlyn missed two days of practice but returned to work on Friday and got the start.
"They just told me I was going to get a chance to start this week," Munnerlyn said.
As for the touchdown, it was the first of Munnerlyn's career.
RB Mike Goodson
"It was good to have Jonathan back out there," coach John Fox said. "He had a couple of heavy runs and moved behind the pads pretty well. It was good to have that one-two punch out there. I haven't seen the stat sheet, but I thought he did pretty well."
As for the decision to stick with Mike Goodson as the starter, Fox cited Goodson's two 100-yard rushing games the last two weeks as the reason.
"It's been his ball, and I didn't think it was time to take it away from him," Fox said.
Goodson didn't disappoint, finishing with 134 yards from scrimmage and scoring his first NFL touchdown against Cleveland.
TRENDING: The Browns hadn't allowed a touchdown on their opening possession in 23 straight games and the Panthers hadn't scored a touchdown in the first quarter all season. So it only figures that the Panthers would take the opening kickoff and go 81 yards for a touchdown to take a 7-0 lead.
--RB Mike Goodson turned in a third straight strong game with 136 yards from scrimmage on Sunday and scored his first NFL touchdown on a 26-yard run. He remained the starter despite the return or Jonathan Stewart. He should start against Seattle.
--RB Jonathan Stewart didn't start but still ran for 98 yards against the Browns and look strong. Coach John Fox said he was impressed with Stewart's running "behind his pads" in his first game in three weeks.
--G Travelle Wharton did not play Sunday.
--S Jordan Pugh sat out on Sunday with a hamstring injury.
--S Marcus Hudson sat out with an ankle injury.
--LG Mackenzy Bernadeau started in place of Travelle Wharton, who has turf toe. The Panthers allowed three sacks.
--DE Charles Johnson has two sacks for the Panthers giving him a team-leading 6.5 for the season.
--LB Jon Beason got his first interception of the season.