Backup quarterbacks have played an unusually outsized role in 49ers history.

Steve Young replaced Joe Montana and extended a dynasty on the verge of fizzling out. Colin Kaepernick took over for Alex Smith and was one throw away from a Super Bowl victory. Jimmy Garoppolo was the backup to Tom Brady before he led the 49ers to the Super Bowl, and incumbent starter Brock Purdy was third on the depth chart before beginning his meteoric rise.

With Purdy and All-Pro left tackle Trent Williams out this week nursing injuries, the struggling 49ers turned to backup Brandon Allen, hoping the veteran journeyman could emulate his predecessors's heroics for this week's game in Green Bay.

The heroics never came.

Allen, playing through a broken middle finger on his non-throwing hand, struggled to produce offensively. He ended the game with only 199 yards and one touchdown.

"I think it took me a minute to get back into it, so we started slow. [It] just didn’t help, didn’t help our defense at all," said Allen at the postgame press conference.

Head Coach Kyle Shanahan's offense failed to play well during key stretches of the game, making uncharacteristic mistakes in moments that would've otherwise swung the game's momentum back in their favor.

Wide receiver Deebo Samuel had an easy throw bounce off his hands, resulting in an interception. Samuel, Allen, and running back Christian McCaffrey also each contributed a fumble.

The 49ers defense and special teams units weren't strangers to miscues either.

In the second quarter, two consecutive penalties by the defense erased a critical interception on Packers quarterback Jordan Love and set up an easy touchdown for Green Bay. The defense also struggled to make tackles throughout the game and dropped multiple potential interceptions.

Then, coming out of the halftime break, Samuel's massive 87-yard kick return was called back because of a holding penalty. The play otherwise would've likely led to some much-needed 49ers points, helping to close the gap at a time when the Packers only led 17-7.

"It’s probably one of the worst ones I’ve been a part of, you know," said linebacker Fred Warner after the game. "It is embarrassing. You got to take it on the chin, take it like a man, and move on.

This loss drops the 49ers to 4-6, leaving their playoff aspirations on life support. They now go on the road to face the 9-2 Buffalo Bills, who beat the then-unbeaten Kansas City Chiefs in their last game and had a bye this week.

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