BREAKING: 49ers’ DE Nick Bosa reportedly tore his anterior cruciate ligament against the Cardinals and could miss the next game, with doctors predicting he could be…

The San Francisco 49ers’ dominant defensive end, Nick Bosa, may have suffered a devastating blow to his season after reports emerged late Monday evening suggesting he tore his anterior cruciate ligament (ACL) during Sunday’s clash with the Arizona Cardinals. Though the 49ers managed to secure a hard-fought victory, the win came at a heavy cost, as one of their most irreplaceable stars now faces an uncertain future.

Bosa, 27, exited the field midway through the third quarter after collapsing awkwardly while attempting to disengage from a Cardinals offensive lineman. Initially, the injury appeared to be minor, with the Pro Bowl pass rusher trying to walk it off. However, as team medical staff rushed to evaluate him, concern quickly grew, and Bosa was helped off the field without putting much weight on his right leg.

The 49ers confirmed post-game that Bosa underwent preliminary imaging, with further tests scheduled for Monday morning. According to insiders close to the team, those examinations revealed a suspected ACL tear—an injury that historically sidelines players for several weeks, sometimes months, depending on severity. While official confirmation has not been released by the organization, multiple doctors familiar with such injuries believe Bosa could miss at least the next game and possibly much longer.

For head coach Kyle Shanahan, the potential absence of Bosa is a nightmare scenario. “Nick means everything to this defense,” Shanahan said after the game. “We don’t want to jump to conclusions until all the test results are in, but obviously we’re worried. He’s a warrior. Our job now is to support him and prepare the rest of the team to step up if we have to move forward without him.”

Bosa’s teammates echoed that sentiment. Veteran linebacker Fred Warner admitted the locker room felt deflated after seeing their leader sidelined. “Nick sets the tone for all of us. When he went down, the energy just shifted. You never want to see your brother in pain, especially someone who puts his heart into every single play. We’re praying it’s not as bad as it looks.”

The timing of the injury could not be worse for the 49ers, who are preparing for a critical stretch of the season. Sitting atop the NFC West, they face a gauntlet of upcoming games against playoff-caliber opponents. Losing their premier pass rusher—even temporarily—would leave a glaring hole in a defense that has been the backbone of their success.

Bosa has been in sensational form this season, racking up multiple sacks, pressures, and tackles for loss that disrupted nearly every offense he faced. Widely regarded as one of the most dominant defensive ends in the NFL, he not only terrorizes quarterbacks but also demands double teams that free up opportunities for teammates. His presence transforms the 49ers’ defensive scheme, and without him, Shanahan and defensive coordinator Steve Wilks will need to rethink their entire strategy.

Medical experts caution that ACL injuries vary in severity. Some partial tears allow for limited recovery within weeks, while complete tears often require surgery and extensive rehabilitation. Dr. Marcus Lee, a sports medicine specialist unaffiliated with the 49ers, weighed in: “If it’s a complete tear, Nick could be looking at a season-ending procedure. But if the imaging shows a partial tear or strain, it’s possible he returns within the next few weeks. Everything depends on swelling, stability, and how his knee responds in the coming days.”

The news has also rippled across the NFL community, where Bosa is respected as both a fierce competitor and a model professional. Social media exploded with messages of support, with fans and fellow players rallying behind the star defender. Arizona’s quarterback Kyler Murray, who faced Bosa throughout Sunday’s game, tweeted: “Hate to see that. Nick is a beast and the game’s better when he’s out there. Praying for a speedy recovery.”

For the 49ers, the immediate focus turns to contingency plans. Depth on the defensive line will be tested, with backups expected to see increased snaps. Veteran lineman Arik Armstead emphasized the team’s “next man up” mentality. “We can’t replace Nick. Nobody can. But we can honor him by playing harder, smarter, and keeping this defense strong until he’s back.”

Despite the grim outlook, Shanahan refused to let the injury overshadow the team’s goals. “We’ve dealt with adversity before. Football is about resilience. We’ll rally. And we know Nick—if anyone can come back stronger, it’s him.”

For now, all eyes remain on the official medical update expected later this week. Whether Bosa’s season is derailed or simply delayed, the 49ers—and the NFL as a whole—hold their breath. One of the league’s brightest stars may be facing his toughest battle yet, not on the gridiron, but in the training room.