Jim Harbaugh has the Chargers looking every bit like a playoff team, and their ground game has quietly become the engine driving that push. But when one of their most critical defensive anchors was suddenly spotted heading to the locker room, you could almost feel Harbaugh’s stomach drop.

Yes, Chargers star Khalil Mack exited Monday night’s matchup against the Raiders early after his left arm was caught awkwardly in a tackle. On the last play of the first quarter, Mack dove to bring down Tre Tucker, but his left arm got trapped in a tough spot between Turner and another teammate, leaving him shaken up. And it looked bad. Really bad. That’s a tough blow for the Chargers, tonight and beyond.

He looked like he knew the second it happened. The moment the play ended, he shot up and sprinted straight for the medical tent. He paused briefly on the sidelines, doubled over in obvious pain, with the training staff rushing to his side. It didn’t look like he was going to return.

Now in Year 12, former Raiders first-round pick Khalil Mack has been a force for the Chargers, earning Pro Bowl honors in each of his past three seasons. This fall marks his fourth season in Los Angeles. The 34-year-old former Defensive Player of the Year racked up 39 tackles and six sacks last season. Even calling his absence a ‘big miss‘ feels like an understatement.

Through his years in L.A. and across his career, Mack’s been a nightmare for quarterbacks: 108.5 sacks to his name. But it’s not just about the numbers; he’s the kind of guy whose presence alone makes offenses commit errors. Not really tactical words of wisdom, but there’s just something about his aura on the field.

The front office mustered up a lot of faith in Mack when they handed him the $18 million deal this offseason. Now, it’s on the 34-year-old to justify those numbers. It was a big risk offering that deal to someone in year 12. It’s not about the ability, but availability. Let’s see how swift his return is. He’s currently out there with his arm heavily bandaged and in a sling. But what does this mean for Jim Harbaugh’s defense and linebacker room?

Who’s going to step up amid Khalil Mack’s absence?

With Mack sidelined and being carted off, the Chargers suddenly lost one of their top edge threats. A spot that’s already shaky after offseason shakeups. They let Joey Bosa walk in the spring, freeing up cap space but leaving their outside linebacker room thinner than ever. That’s exactly why bringing Mack back was such a big deal. So who’s stepping up to play those snaps?

The Chargers were already getting their younger guys ready in camp and early-season reps. Tuli Tuipulotu was set for a bigger role in 2025, and Daiyan Henley has been quietly climbing the depth chart, making quite a name for himself in the linebacker room. But are those options good enough?

Well, Mack himself thinks so. “Tuli is a special player. I’ve been saying that ever since he stepped foot in the building three years ago. Just knowing who he is and knowing what he brings on a consistent basis, he’s already ready for that. He’s been a starter essentially for the past three years. I don’t think it’s going to be any different just knowing how he’s approaching the game this year and how detailed he is in his technique and everything,” he said about Tuipulotu.

As for Henley, he really burst onto the scene in 2024. After earning the starting job in training camp, he led the Bolts in tackles, showed off his coverage skills, and quickly became one of the rising stars at his position in the league. Safe to say, these options won’t force Harbaugh to ring the alarm bells. But of course, the sooner Mack arrives, the better.