The San Francisco 49ers couldn’t keep up with the Detroit Lions in their home finale on ‘Monday Night Football’ in Week 17. They lost 40-34, their 10th loss in an injury-riddled 2024 season and their sixth in the last seven games.

They can potentially add another injury to the list: quarterback Brock Purdy.

Purdy had a career-high 377 passing yards in the game but left late in the fourth quarter after a sack by Lions safety Brian Branch.

After the play, Purdy left the game and was replaced by Joshua Dobbs, who scored on a 7-yard touchdown run on the 49ers’ final drive of the game.

San Francisco coach Kyle Shanahan said after the game that Purdy’s status for Week 18 against the Arizona Cardinals is up in the air due to a nerve issue in his elbow.

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Purdy will undergo more testing Tuesday.

At 6-10, the 49ers are out of playoff contention this season.

If he’s out, he’ll be the latest significant injury to the 49ers’ offense. San Francisco played Week 17’s game against the Lions without left tackle Trent Williams and left guard Aaron Banks.

Running back Christian McCaffrey and wide receiver Brandon Aiyuk have both missed significant time with injuries as well.

49ers QB depth chart

San Francisco went to Dobbs after Purdy’s injury. The team also has quarterback Brandon Allen on the active roster. Allen started for Purdy in Week 12 against the Green Bay Packers and struggled in a 38-10 loss.

It’s unclear whether Dobbs or Allen would start in Week 18 if Purdy is out.

The 49ers also have quarterback Tanner Mordecai signed to the practice squad.

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