The Carolina Panthers agreed to terms with quarterback Cam Newton on Thursday, the team announced, reuniting the franchise with its career leading passer and one of its most popular players less than two years after it released him.

The move adds stability to the Panthers after their starting quarterback, Sam Darnold, injured his right shoulder on Sunday against the New England Patriots. Darnold is expected to miss multiple games. The Panthers’ backup, P.J. Walker, has started only one game in his two-year pro career, and the team recently signed the journeyman Matt Barkley.

After the Panthers cut Newton, the Patriots signed him in July 2020, and he started 15 games for them last season. But the Patriots released him near the end of this training camp, electing to start a rookie, Mac Jones, whom the team drafted No. 15 overall this spring. In August, a misunderstanding of Covid-19 protocols forced Newton to miss several days of practice — a sign that he had not been vaccinated. His absence allowed Jones to practice with the Patriots’ starters.

Newton’s vaccination status also made it tougher for potential suitors to sign him. Unvaccinated players must test negative for five days before entering team facilities. In October, on his YouTube Channel, Newton confirmed that he had been vaccinated and was ready to join a team.

“I still want to play football,” Newton said. “I still get that urge to go out and perform and do something that I’ve been doing since I was 7 years old.”

ESPN and the NFL Network reported that the deal was a one-year contract worth up to $10 million. Team officials and an agent for Newton did not immediately respond to messages seeking comment.

The Panthers drafted Newton with the No. 1 overall pick in 2011, and he quickly became a cultural fixture in Charlotte, N.C., for his demeanor, fashion sense and highlights on the field. He won the Rookie of the Year Award and earned three Pro-Bowl nominations. In 2015, he won the N.F.L.’s Most Valuable Player Award and led the Panthers to a 15-1 regular-season record and a Super Bowl appearance.

His career slipped after that. The Panthers made the playoffs only once from 2016 to 2018, and Newton played through nagging injuries and struggled with his passing accuracy. In 2019, he sustained a serious foot injury that limited him to two games. After a new regime took over the Panthers’ front office and coaching staff, the Panthers released Newton in March 2020.

When the Patriots signed Newton it was to a one-year, incentive-based deal, a cheap price for a potential successor to Tom Brady, who had joined the Tampa Bay Buccaneers after two decades in New England. Newton missed only one start for New England — because he contracted the coronavirus — and completed 65.8 percent of his passes and rushed for 12 touchdowns. But the offense limped through the season because it lacked elite skill players. Still, the team re-signed him this spring to keep a proven veteran on the roster.

The Panthers, meanwhile, also faced trouble replacing Newton. They signed Teddy Bridgewater last season, but the quarterback performed poorly late in games, contributing to a 5-11 record. David Tepper, the team’s owner, was said to be interested in Deshaun Watson, too, before Watson faced lawsuits accusing him of sexual assault and misconduct.

In April, the team traded for Darnold, believing the former Jets quarterback would succeed in a new environment with better coaching and offensive weapons. That theory worked initially as the Panthers won their first three games of the season. But they have lost five of the last six, and Darnold is tied for the league lead in interceptions with 11. On Oct. 24 against the Giants, Coach Matt Rhule benched Darnold in the fourth quarter. When asked this week about potentially signing Newton in the wake of Darnold’s injury, Rhule deflected.

“I won’t get into any hypotheticals. I’ll just probably just talk about the guys on the roster,” Rhule said.

Now, Newton is a guy on the roster.