MIAMI -- Cam Newton's storybook beginning to his second stint with the Panthers came to a crashing halt Sunday when he was benched in the fourth quarter of Carolina's 33-10 loss to the Miami Dolphins.

Newton was replaced by P.J. Walker with just over 10 minutes remaining and the Panthers trailing by 20.

Coach Matt Rhule said he told Newton the switch was made because the Panthers (5-7) were in hurry-up mode and Walker had a better grasp of the two-minute offense.

Rhule said he doesn't expect a quarterback change after Carolina returns from its bye.

"At the end of the day, we weren't protecting the quarterback at all,'' he said. "It wouldn't be fair to keep Cam in there and keep getting him hit.''

Also, Carolina running back Christian McCaffrey suffered a left ankle injury in the second quarter and played only one snap in the second half. The South Florida Sun-Sentinel reported that McCaffrey was wearing a walking boot as he left the stadium. Rhule said he did not immediately know the extent of the injury for McCaffrey, who missed 13 games last season with injuries and five games this season with a hamstring injury.

McCaffrey saw his streak of catching at least one pass in 57 consecutive games in which he has played snapped. That streak was tied for the longest by a back since Theo Reddick had 57 from 2014 to 2018, per ESPN Stats & Information research.

The Panthers gave up five sacks, but only one of those was on Newton. The 32-year-old quarterback, however, was hit countless other times and had several passes tipped at the line of scrimmage.

Newton refused to blame his performance -- he completed 5 of 21 pass attempts for 92 yards with two interceptions for a passer rating of 5.8 -- on his protection.

He understood why the change was made.

"I was fine with that,'' he said. "At the end of the day, it's still about being a professional. At that particular point, I had more than enough opportunities to keep the game in the balance. There's no need to put up a fight with that.''

The Panthers are 0-2 with Newton as the starter, but until Sunday his performance had been solid. Newton's 23.8 completion percentage was the worst by a player with 20-plus attempts since 2004, according to ESPN Stats & Information research.

Detroit's Joey Harrington completed 22.7% against Green Bay that year.

It was the worst completion percentage by a former NFL MVP with a minimum of 20 pass attempts ever, according to Elias Sports Bureau data. Peyton Manning (25.0, 2015) previously had the record, followed by Brett Favre (30.4, 1999) and Roman Gabriel (30.4, 1975).

"This is the NFL,'' Newton said. "Nothing is promised. Just because Cam Newton is on your roster doesn't mean you're going to win. Just because it's a feel-good story doesn't mean you're going to win."

Newton's poor performance came less than three weeks after he was signed to a one-year deal that could pay him up to $10 million for the rest of the season if he meets incentives. He scored the first two times he touched the ball in relief of Walker in a win at Arizona four days after rejoining the team that made him the top pick of the 2011 NFL draft.

He had two touchdown passes and a rushing touchdown in last week's 27-21 loss to Washington.

It all fell apart on Sunday after Newton scored on a 1-yard run that made it 7-7.

Rhule called it a poor day "all around.'' Newton said he plans to use the upcoming bye week to dive deeper into the offense so what happened on Sunday doesn't happen again.

"Today, it really got exposed because of the situation, not having a full grasp,'' Newton said. "It's not nobody to blame, more so the situation I came into. Having this week to kind of self-scout and dive into what the root of this offense is all about, that's what I plan on doing.''