CHARLOTTE, N.C. — Panthers coach Ron Rivera said C.J. Anderson's frustration with his smaller-than-expected role on offence contributed to the team's decision to release the former 1,000-yard rusher midway through the season.

Rivera said he spoke recently to Anderson and could sense the veteran running back's frustration over not being more involved in Carolina's offence.

Christian McCaffrey is the team's starter and rarely leaves the field, playing in 96 per cent of his team's offensive snaps — by far the most of any running back in the league.

Most of Anderson's reps have come in a shared backfield set with McCaffrey the Panthers called "Pony 21." Anderson has carried the ball just 24 times and caught one pass this season. The limited role came just one season after Anderson ran for 1,007 yards for the Broncos.

"He's a veteran guy who has had a lot of success in this league and was just looking for more opportunities," Rivera said Tuesday, one day after the Panthers released Anderson. "You could feel" the frustration.

Rivera reiterated what general manager Marty Hurney said Monday — that Anderson did not ask to be released from the Panthers (6-3), who visit the Lions on Sunday after a 52-21 shellacking at the hands of the Steelers last week.

Anderson tweeted Monday: "No love lost. Thank you Carolina. Grind time."

Rivera said Cameron Artis-Payne will take over Anderson's role as the No. 2 back in Carolina.

Artis-Payne was a fifth-round pick in 2015, but has played in just 25 games and carried the ball only 99 times during his career for 422 yards with four touchdowns.

Rivera believes Artis-Payne, who has only been active for two games this season, has a similar skillset to Anderson and can also come in and spell McCaffrey during games. Carolina also signed veteran running back Travaris Cadet, a player Rivera views as similar in style to McCaffrey as a backup plan.

Rivera called Artis-Payne "a tough, hard-nosed young man" who has gone about his role the right way in practice despite not seeing much playing time.

"He's waited for his opportunity and earned this opportunity, and hopefully when he gets his chance on the football field he will take advantage of it," Rivera said.

Rivera said the Panthers offence evolved this year under first-year offensive co-ordinator Norv Turner, and that things began to focus around McCaffrey as the primary, if not exclusive, back on offence — similar to how Turner extensively used LaDainian Tomlinson when he coached the San Diego Chargers.

McCaffrey's expanded role isn't a huge surprise.

Rivera said before the season that getting the second-year back 25 to 30 touches per game would be "ideal," although few could have imagined that he'd leave the field as infrequently as he has this season.

"The more Norv got to know who Christian is, the more we saw we could keep him on the field," Rivera said. "A lot of things that we can do are structured around his skillset."

McCaffrey leads the Panthers with 579 yards rushing, followed by Cam Newton with 352 yards and wide receiver D.J. Moore with 122.

Anderson, who had been expected to be used as a short-yardage back, had 104 yards rushing and no touchdowns on the ground in nine games. His lone reception went for a 24-yard touchdown.

McCaffrey said Anderson's release was a reminder the game is a business.

"Our coaches have a lot of confidence in the guys that are here right now and they had to make a decision they felt was best for the team," McCaffrey said. "As far as we are concerned we have to focus on the guys here and wish him the very best. Our guys right now are just locked into us."

___

For more NFL coverage: https://apnews.com/NFL and http://www.twitter.com/AP_NFL