Jan 5, 2025; Glendale, Arizona, USA; San Francisco 49ers defensive end Nick Bosa (97) against the Arizona Cardinals at State Farm Stadium. Mandatory Credit: Mark J. Rebilas-Imagn Images Mark J. Rebilas-Imagn Images

49ers Lose Star Defender vs Cardinals

Originally posted on Arizona Cardinals on SI
By Donnie Druin | Last updated Sep 21, 2025 5:11 PM ET

The San Francisco 49ers saw star pass rusher Nick Bosa exit action early in their Week 3 contest against the Arizona Cardinals.

He is officially questionable to return with a knee injury.

Bosa appeared to injure his right leg on Arizona's second offensive drive of the game and hobbled off the field in the first quarter. He was being looked at by trainers on the sideline before entering the blue medical tent.

Nick Bosa got off the field and immediately went down. pic.twitter.com/9M20fuUi0b
— SM Highlights (@SMHighlights1) September 21, 2025

According to the FOX broadcast, Bosa spent some time in the blue medical tent before exiting and giving somebody the thumbs down while speaking with 49ers medical staff.

Bosa, a five-time Pro Bowl player, has been one of the league's top pass rushers since entering the league in 2019, bringing down the quarterback 64.5 times leading into today.

Speaking with reporters ahead of their matchup, Bosa said he received some advice on how to counteract Kyler Murray's athleticism

Nick Bosa signaled a to someone in the crowd after he was shaken up with a possible injury. pic.twitter.com/82bo7OeDZL
— Alex Tran (@nineralex) September 21, 2025

“Somebody said... be patient while rushing. And it is kind of counterintuitive when you’re rushing something, to be patient,” Bosa said Wednesday. “He likes to bail back, he likes to spin out, so you just have to be aware.

“I’m excited about the plan this week and I think [defensive coordinator Robert] Saleh’s been good at it before, so he’s got some good tricks up his sleeve."

Bosa has sacked Murray twice during their NFC West battles through the years.

This would be a massive blow if Bosa is knocked out for the entire game - as he was winning consistently against Arizona backup left tackle Kelvin Beachum - who is filling in for an injured Paris Johnson Jr. today.

Now, 49ers defensive coordinator Robert Saleh will be forced to adjust without one of his best players on the field.

"He’s fast, he’s elusive, he’s a jitterbug and he’s also a passer first,” Saleh previously told reporters on Thursday when discussing Murray.

“He’s not just looking to run. He’s looking to buy some time to be able to put the ball in the air. He’s as challenging as it gets.”

Injury issues are nothing new for the 49ers, who have dealt with more than their fare share in recent memory. They previously ruled out names such as Brock Purdy and Jauan Jennings on the offensive side of the ball.

Both the Cardinals and 49ers were 2-0 entering Sunday. Winner will stay atop of the NFC West.