CHARLOTTE, N.C. -- Carolina Panthers coach Ron Rivera said following Sunday's 38-10 loss to the Baltimore Ravens he wouldn't tolerate "a loss of composure" on defense and would make changes if necessary.

He made the first on Monday.

Rivera said Josh Norman would replace Melvin White as the starting right cornerback for Sunday's home game against the Chicago Bears, who have a pair of big receivers in 6-foot-4 Brandon Marshall and 6-3 Alshon Jeffery.

White lost containment that led to two touchdowns by former Carolina wide receiver Steve Smith, who caught seven passes for 139 yards at M&T Stadium.

Norman replaced White after Smith's second touchdown and played the rest of the game. He finished with 44 defensive snaps after playing just 27 in the first two games.

"I thought he played pretty well," Rivera said. "There were a couple of times where you'd like to see him squeeze the routes a little bit more. I thought a couple times he was a little undisciplined with his eyes. I thought his positioning and his vision was very good. It's all part of the shakeup."

The Panthers have fallen from fifth in the NFL in total defense to 23rd after allowing 37-plus points in consecutive weeks for the first time since 1998.

"If there's going to be changes, we've got to make some changes," Rivera said. "We've got to send some messages and some clear cut ones that, 'Hey, we've got to play at a consistently high level.'"

Norman started 12 games as a rookie out of Coast Carolina in 2012. He was benched after having a performance against Kansas City similar to what White had against Baltimore.

He hasn't started since.

Rivera said the decision to replace White doesn't mean he will be pushed aside.

"Melvin will play; Melvin will get opportunities," he said. "We're not throwing anybody to the side as much as we're just going to say, 'Hey, we just want to give this guy a few more opportunities earlier in the game.'"