The San Francisco 49ers lost to the Green Bay Packers 38-10 in Week 12. With Brock Purdy on the shelf, Brandon Allen and the offense struggled at Lambeau Field. While the NFC West is very tight, the season is slipping away from Kyle Shanahan's squad. Why are Allen, Christian McCaffrey, and the 49ers defense most to blame for their sixth defeat?
The Packers got the ball to start this game and began the blowout immediately. They marched down the field in 12 plays, taking up 7:25 before a Tucker Kraft touchdown. After a three-and-out from San Francisco's offense, Green Bay scored again to break the game open. They never looked back, as the 49ers never closed the lead beyond 10 points. This was the largest loss the Niners have suffered since 2018, which is why the blame falls on both sides of the ball.
How can the 49ers improve to make the playoffs? And where did they go wrong against the Packers? Here are our players to blame for this key game.
Brandon Allen never had a chance

Late in the week, the 49ers scratched Brock Purdy due to a shoulder injury. Brandon Allen is in his eighth season out of Arkansas and had made nine starts in the NFL before Sunday. He sat behind Purdy and Sam Darnold last year and won the backup job this season. But in his first start since 2021, he looked overmatched and not ready for the big moment.
Allen made costly mistakes, including a massive interception, and was very inaccurate. This is unlike performances we have seen from Shanahan-era backups. Brock Purdy was one himself before stealing the starter's job back in 2022. The coaching staff is usually able to cook up a quarterback-proof scheme that can scrape out an ugly win. That was not the case against the Packers.
Things will not get easier for Allen if he is asked to stay in. The 49ers are in primetime next week against the Buffalo Bills, which will be similar in terms of temperature and environment. Allen and the coaches need to get in the lab and figure out the issues before that matchup. If Purdy is back, the 49ers still have to scheme more receivers open and protect their quarterback better.
Christian McCaffrey does not look like himself
The 49ers went the first eight games of their season without star running back Christian McCaffrey. The 4-4 record was partly because their back was out. Jordan Mason was third in the league in rushing, but surely McCaffrey was going to unlock the offense. It's safe to say that has not been the case so far, as he struggled again on Sunday.
With 31 yards on 11 carries and a fumble, he continued his struggles on the ground. Meanwhile, Mason took his one carry for 15 yards. The 49ers have not run the ball well since getting McCaffrey back, so could it be time to get Mason more involved? Despite the obvious advantage McCaffrey gives the passing game, it might be time to split the carries.
The Bills run the ball well and defend the run well. While they did beat the Chiefs, they have their flaws that the Niners would expose in a normal season. This 49ers team is not the traditional Niners team that would expose a flawed team because McCaffrey has not run the ball well.
The 49ers' defense continues sluggish season
The 49ers have had tremendous injuries on offense but their defense has been relatively healthy. That was not the case in this game, as Nick Bosa was out. An already struggling unit missed their top pass rusher in this game. Without Bosa, Jordan Love had plenty of time to throw and Josh Jacobs dominated on the ground. Without their patented strong defense, the 49ers have no chance of making the playoffs.
As the weather gets colder, defenses get more important. It's one of those things your dad used to say that sounds ridiculous but is undeniably true. And as the weather gets colder, the 49ers defense gets worse. Their matchup with the Bills could expose them even further and put a nail in their playoff coffin. Fred Warner and crew must step up and snag the win in their next game.
Even with all of these struggles, the 49ers are one game out of first place in the NFC West. With games remaining against the Rams and Cardinals, this season is not over. Each of these units must improve to sneak into the playoffs and potentially cause chaos in January.