The San Francisco 49ers have agreed to a one-year deal with former Carolina Panthers quarterback Sam Darnold, a source told ESPN's Adam Schefter.

He bolsters the 49ers' depth at quarterback with Jimmy Garoppolo's exit to the Las Vegas Raiders and both Brock Purdy and Trey Lance returning from injuries.

Darnold, 25, took a step last season toward rebuilding his career that had been on a downward spiral since being selected with the third pick of the 2018 draft.

He went 4-2 over the final four games for the Panthers after being activated from injured reserve, threw seven touchdowns to three interceptions and rushed for two touchdowns.

It was a stark contrast from the player that went 13-25 in three years with the Jets, throwing 45 touchdown passes to 39 interceptions after a stellar college career at USC.

He also showed improvement from his 2021 season with Carolina in which he went 4-7, throwing 13 interceptions to nine touchdowns.

The Panthers acquired Darnold in a trade with the Jets during the 2021 offseason, believing a change of scenery would help revive his career. He went 3-0 before losing eight of his last nine games, missing six starts with a shoulder injury.

Carolina traded for Baker Mayfield, the first pick of the 2018 draft, to compete with Darnold for the starting position last season. Darnold lost the job in training camp and then suffered a high ankle sprain in the final preseason game. He began the season on injured reserve and didn't get a chance to play until late in the season after Mayfield was released after going 2-8 as the starter.

Darnold credited his improvement last season in part to spending a lot of time while on injured reserve with defensive players to get a different perspective.

ESPN's David Newton contributed to this report.