The defense of the 49ers has been superb for most of the season.
Outside of their performance against the Chiefs, they have been top-notch. No one has been able to gash them for much of anything. Meanwhile, the offense has been mediocre to average for a majority of the season. The only reason the 49ers have been in games is thanks to the defense.
DeMeco Ryans has his side allowing 15.8 points per game, which is No. 1 in the league. They have alloted the offense a significant margin for error each and every week. It's why they don't need to score many points. And now that Jimmy Garoppolo is out for the season, the defense will be responsible for success the rest of the way indefinitely.
The 49ers will only go as far as their defense takes them.
If the defense cannot maintain its high-level elite form, then the 49ers will lose. It will mean the offense will be demanded to produce more points and that just isn't going to happen with Brock Purdy. It wasn't even happening with Garoppolo, but at least Garoppolo was taking care of the football and had few negative moments.
Purdy is a backup quarterback who was a borderline undrafted free agent. I am shorting any idea of him playing at a solid level for the 49ers. He may be sufficient at times or even for the next couple of games, but eventually backup quarterbacks end up getting figured out easily. Stalled drives from the offense that come away with zero points will likely increase. Everything will depend on the defense as it has all season long.
I just have concerns that the defense will not be able to sustain this strong form they are in. Against the Dolphins, they easily could have been picked up if Tua Tagovailoa wasn't so anxious in the game. It was clear he was tense with the playoff atmosphere on the road against a good defense. He didn't just miss a few throws to open wide receivers -- he missed a boatload. Someone like Tom Brady, who they are facing this week, is probably not missing those.
What happens when the 49ers defense faces a quarterback who doesn't mess up those opportunities?
They will need the offense to help by sustaining drives and putting up points so that they too can finally be allotted a margin for error. I just don't believe that is ever going to be the case for the 49ers defense. In the playoffs, the offense will probably have to face at least one of the elite defenses in the Cowboys or Eagles. They will certainly struggle, especially if it is a game where they have to put up 20 points. Maybe I'll be proven wrong and the drop-off from Garoppolo to Purdy is miniscule. But I am not a believer in that.
All season long since Week 3 against the Broncos, I have pounded the table that the defense needs to be elite all year long or the 49ers will lose more games. For the most part, they have been elite, but there are opportunities to be had against them. They have just been fortunate to not have faced any threatening quarterback. And the one that they did in Patrick Mahomes, he and the Chiefs ended up dropping 44 points on them. It really isn't fair to have it all laid on the defense, but it is the only shot for the 49ers to go far into the playoffs.