49ers' Brock Purdy Out with Shoulder Injury; Brandon Allen to Be QB1 vs. Packers

San Francisco 49ers quarterback Brandon Allen will start for injured starter Brock Purdy on Sunday at the Green Bay Packers, per head coach Kyle Shanahan to reporters.

Purdy is dealing with soreness in his right (throwing) shoulder stemming from his team's recent 20-17 home loss to the Seattle Seahawks, per Shanahan on Monday (h/t ESPN's Nick Wagoner).

"I don't want to say there's long-term concern," Shanahan told reporters, per Wagoner. "We thought he just needed some rest and we really weren't concerned about [him] not being good this week. But when he started up Thursday, it just surprised him, surprised us with how it felt. So, we had to shut him down. I really don't know what to think of it. ... But the way it responded this week, it's really up in the air next week. We'll have to see on Monday."

Purdy was a limited participant in practice on Wednesday and Thursday, but he was wasn't on the field in uniform during the early open portion of practice Friday.

Joshua Dobbs, who most recently excelled with the Minnesota Vikings last year after briefly taking over for an injured Kirk Cousins, will serve as Allen's backup.

The 32-year-old Allen has played in 16 games (nine starts) over five seasons (2019-2022, 2024) for the Denver Broncos, Cincinnati Bengals and 49ers. He's completed 56.7 percent of his passes for 1,611 yards (6.1 yards per attempt), 10 touchdowns and six interceptions.

Allen enters a tough road environment against a 7-3 Packers team that looks bound for the playoffs. He also may be without superstar left tackle Trent Williams, who suffered an ankle injury in Week 10 and has missed practice all week.

Worse yet, the 49ers will be more shorthanded on the defensive end with star edge-rusher Nick Bosa out with an oblique/hip issue, per Shanahan.

So San Francisco will go into this game as a significant underdog. It's already been an inconsistent season for the 5-5 49ers, who have notably been mediocre on the defensive end (16th in points per game allowed).

The offense is still a respectable eighth, and that's without running back Christian McCaffrey as he dealt with Achilles tendinitis that kept him out for the first eight contests. But the defending NFC champions certainly expected more after entering the year with Super Bowl aspirations.

That's still feasible, especially with no team running away with the NFC West. The 6-4 Arizona Cardinals currently lead the way, so the 49ers can catch them, grab a home game in the wild card round and make a run at it.

But San Francisco has Green Bay and then the 9-2 Buffalo Bills on the road back-to-back. If Purdy is forced to sit another game, San Francisco could find itself at 5-7 and needing to run the table to make the playoffs.

For now, the 49ers hope Allen could do well enough in Purdy's absence to grab a win in Green Bay. Kickoff is set for 4:25 p.m. ET in Lambeau Field.