Nick Bosa injury update gives 49ers the worst gut punch possible

San Francisco 49ers fans must have had some flashbacks to the early portion of the 2020 season when they watched star rookie defensive end Nick Bosa suffer a torn ACL in Week 2's bout against the New York Jets.

This go-around, Bosa exited the Niners' Week 3 home tilt versus the Arizona Cardinals with a knee issue that ultimately sidelined him for the rest of the game. And it appeared San Francisco's top pass-rusher knew something was seriously wrong early even before he made his way back to the locker room for further evaluation.

Following the 49ers' 16-15 victory, head coach Kyle Shanahan told reporters the initial diagnosis didn't indicate a torn ACL, but further testing had to be performed.

According to ESPN's Adam Schefter, that initial diagnosis was incorrect, and further tests revealed a season-ending ACL tear:

Brutal.

How do 49ers get by without Nick Bosa?

Unlike last season, when then-defensive coordinator Nick Sorensen failed to adjust after a separate Bosa injury that kept him out of games, coordinator Robert Saleh managed to alter his in-game approach enough to account for Bosa's absence.

Plus, the combination of less-known defensive ends, such as Bryce Huff and rookie Mykel Williams, was enough to ensure Arizona's offense wasn't able to get into a rhythm for the bulk of the NFC West showdown.

Huff, who recorded the Niners' lone sack of the day, is effectively Saleh's best pass-rusher with Bosa sidelined, while Williams' own maturation will be an element to watch in the coming weeks.

That said (and Saleh has already shown a knack for doing so), one might expect San Francisco to send more than four rushers than usual to account for Bosa being out. Through three weeks, the 49ers are blitzing on just 9.4 percent of pass plays, which is tied for fifth lowest.

This number is likely to increase, beginning with Week 4's home showdown against the Jacksonville Jaguars, who have only surrendered three sacks to quarterback Trevor Lawrence to date.

In an ideal world, Saleh and Co. would have a healthy Bosa to rely upon.

Now, they don't.