Aaron Rodgers got the news on Tuesday that was widely feared since he departed the Jets’ Monday night game against the Buffalo Bills: He had torn his left Achilles’ tendon and will miss the season, the league said in a social media post.

After a long and glittering career as the Green Bay Packers quarterback, Rodgers had come to the Jets at age 39 in the hopes of pushing the team to a Super Bowl, which the franchise had not won since the days of Joe Namath. Already stocked with an elite defense and young stars at key positions, Rodgers’s experience and leadership were thought to be the final puzzle piece to a team that could contend for a championship.

But the star quarterback was sacked just three and a half minutes into his first game at MetLife Stadium on Tuesday. Though he stood for a moment after being felled by Bills defensive end Leonard Floyd, he soon sat down on the turf. He was helped to the sideline then carted off to the locker room and TV cameras showed Rodgers wearing a protective boot.

After the game, Jets Coach Robert Saleh said he expected medical scans to confirm a suspected season-ending injury. “It’s not good,” he said.

On Tuesday, that confirmation came, the league said in a post on X, formerly known as Twitter, citing two N.F.L. Media reporters. The Jets said in a post: “Not the way any of us wanted it to go, but we know the commitment you’ve made to this team will continue to impact us moving forward.”

The Jets have had a star-crossed history since Namath led them to an upset Super Bowl victory in 1969. There have been several good seasons, and even some playoff runs, but no return to glory.

There was hope that could change this season after Rodgers was acquired in an April trade in exchange for draft picks. His long career has put him in the top 10 of many passing categories, he has won four Most Valuable Player Awards, and in the 2010 season he took the Packers to their only Super Bowl victory of this century.

The fit seemed good: Rodgers threw himself into the life of the city, turning up at the Tony Awards, Knicks and Rangers games, the U.S. Open, and a Taylor Swift concert at MetLife.

For now, the Jets turn to their backup quarterback, Zach Wilson, who helped the team rally to a 22-16 win in Monday’s game against the Bills.

But with Rodgers’s absence, expectations for the Jets are now, as in so many other years, severely diminished.