Carolina Panthers quarterback Cam Newton sat out practice on Tuesday and could miss Sunday’s game against the Arizona Cardinals after aggravating a foot injury on Thursday.

General manager Marty Hurney and head coach Ron Rivera told reporters Newton said his foot was sore following the team’s Thursday night loss to the Tampa Bay Buccaneers.

The 30-year-old sprained his left foot in a preseason game last month against the New England Patriots.

Team-mate Eric Reid said Newton has been in a walking boot.

Rivera revealed Newton underwent treatment over the weekend, and the coach and quarterback met again on Tuesday morning to reassess.

“He was low about it, he really was. He wants to compete so badly,” Rivera said.

“It’s tough. He wants to be out there for his team-mates. I appreciate our conversation. He was very honest and he was upfront about it. He said he’s going to do everything he can. We’ll see what happens.”

Asked about a timeline for Newton’s return, Rivera replied: “I have no idea.”

Kyle Allen is No 2 on the Panthers depth chart at quarterback Kyle Allen is No 2 on the Panthers depth chart at quarterback Kyle Allen is No 2 on the Panthers depth chart at quarterback

If Newton sits against the Cardinals (0-1-1), the 0-2 Panthers will start Kyle Allen at quarterback.

“I think Kyle’s more than ready,” Rivera said. “I think Kyle did some really good things last year, showed us what he’s capable of. He had a good preseason. Had a whole bunch of ups, had a few downs, but for the most part, he knows the offense, he knows it very well.

“So we feel confident about him, we really do.”

Allen appeared in two games (one start) in 2018, going 20 of 31 for 266 yards and two touchdowns. In the preseason this year, he went 18 of 34 for 165 yards with no touchdowns or interceptions.

The Panthers drafted Will Grier in the third round of April’s draft, but he has yet to be active through two weeks. Rivera said the team is unlikely to add a veteran.

“I don’t think so,” Rivera said. “The guys we have here, we brought them here for a reason.”

Newton was 25-of-51 passing for 333 yards in a loss last Thursday to the Tampa Bay Buccaneers. He was sacked three times and lost a fumble.