San Francisco Is 3-0 and Sinking — and Nick Bosa's Calf Is Only Part of It

The 49ers are unbeaten, and the tape says they're getting worse.

San Francisco sits 3-0 with a plus-16.0 point differential, a 32.7-point scoring average and a plus-78.7 yardage margin per game. Brock Purdy has thrown for 789 yards with nine touchdowns against one interception, a 72.3 completion rate and a 133.1 passer rating. By any box-score measure, this is a team rolling toward its Week 4 date with Denver at Levi's Stadium.

Then there's the number that matters more: Earl's model has San Francisco at No. 2 with an 8.0 rating, down 3.7 points from Week 2 — when the Niners actually sat at No. 1 with an 11.7 mark. The record is pristine. The underlying profile is sliding. And the news cycle over the past week explains why.

The Bosa problem

Nick Bosa suffered a calf injury in Thursday's practice, reported by ESPN's Adam Schefter, and is expected to miss multiple weeks. The 49ers have reportedly weighed whether to place him on injured reserve, a decision complicated by an already absurd injury list. This is a five-time Pro Bowl edge rusher — and it's worth being precise about what he's been this season. Through three games, Bosa has zero sacks and one quarterback hit. The calf doesn't erase a pass rush that was already thinned out; it removes the player who commands attention anyway.

That distinction matters. San Francisco has generated just six sacks and 18 quarterback hits as a team. Keion White leads the group with 2.0 sacks, Ogbonnia Okoronkwo has 1.0, and Romello Height — currently dealing with a hand issue — has 1.0. Raheem Morris' defense has leaned on disguise and diverse pressure sources rather than winning one-on-ones, and the article on Upton Stout's role highlighted exactly that creativity. Asking Morris to keep manufacturing pressure without his best edge defender is a different job entirely.

The reinforcements are a practice-squad patch

The 49ers responded by signing four-time Pro Bowl pass rusher Matt Judon — to the practice squad. Judon posted 5.5 sacks in 2024 and arrives as an experienced rotational option, but the framing from the reporting is honest: he's a stopgap while bodies return. This is what a defensive line room looks like after Alfred Collins' season-ending patellar tendon tear in September, a blow that landed before the season even started.

Linebacker depth is a related worry. Fred Warner has publicly discussed the run defense's struggles — San Francisco sits 17th in rush success rate and 12th in EPA per rush — and Los Angeles and Miami both had stretches where they ran the ball at will. Injuries have zapped the front's depth, which is precisely the situation Bosa's absence deepens.

What it means for the Broncos — and beyond

Denver arrives with a sputtering offense: 20.0 points and 282.7 yards per game, 81.0 rushing yards per contest, and Bo Nix completing 60.2 percent with four touchdowns, three interceptions, a 80.3 rating, five sacks taken and three fumbles. On paper, that's a get-right opponent for a wounded defense, and the market's Week 4 line — San Francisco around -2.5 with a 47.5 total, moving up from a 46.5 open — reflects a team still favored despite the attrition.

But the broader schedule isn't forgiving. Seattle in Week 5, Washington in Week 6, Atlanta in Week 7. Each of those offenses can test a pass rush that is now dependent on scheme rather than talent off the edge.

The offense can carry a lot — Purdy's efficiency is genuinely elite right now, and the unit is averaging 399.3 yards per game. But the 36-30 escape against Arizona already showed the margin for error shrinking. A 3-0 team that lost 3.7 points of rating in a week is telling you something the standings won't: San Francisco is winning, but it is also leaking.