49ers’ trio of rookies along defensive line could be starters

SANTA CLARA, Calif. — After returning to the San Francisco 49ers as defensive coordinator for a second stint, Robert Saleh was under no false impressions about what the job would entail.

Coach Kyle Shanahan told Saleh in January that he wouldn’t be taking over the veteran-laden defense the team deployed in 2024. The message delivered to Saleh was that the Niners were going to, in many ways, be starting over on defense with most of their additions coming from the draft, especially on the defensive line.

In free agency, San Francisco released defensive tackles Javon Hargrave and Maliek Collins and traded end Leonard Floyd. Each had been a starter in 2024.

That opened the door for the 49ers to spend three of their first five picks on defensive linemen Mykel Williams (No. 11 overall), Alfred Collins (No. 43) and CJ West (No. 113) out of Georgia, Texas and Indiana, respectively.

Other recent Niners teams might have allowed that trio to take time to develop. This group doesn’t have time for that.

“I think of all the major sports, the NFL relies on rookies more than any of them,” Saleh said. “You come in and it’s like throw your kiddo in the water and just go swim. Those rookies, they’re going to make mistakes. The hope is that they can acclimate well enough where they don’t make the same mistake twice … But you throw them in.”

Saleh’s defense could have as many as eight new starters in 2025 with three obvious openings on the defensive line alongside star end Nick Bosa.

More than two weeks into training camp, it’s clear that, barring injury, Williams is going to start opposite Bosa. With injuries to other, older options at tackle, there’s at least one spot for Collins or West to grab hold of another starting spot with West trending positively that direction.

As a group, the early returns on the Niners rookie trio have been good, though Collins has lagged behind Williams and West in part because he missed all of their organized team activities with a calf injury.

Williams was slowed a bit in the spring and missed a practice in camp because of an ankle issue, but he has mostly been as advertised. Saleh inserted Williams as a starter nearly from the moment camp started and he has remained throughout.

At Georgia, Williams lined up on the outside shoulder of the offensive tackle on 22% of snaps he took in 2024. For the Niners, he will do it much more. The transition has been smooth against the run, but he’s got some learning to do when it comes to rushing the passer from the edge.

Saleh said Williams is more comfortable getting after the quarterback rushing from the inside right now, which implies that the rookie could line up outside on run downs and move inside in clear passing situations.

“He’s a three-way player,” Saleh said. “He can run around you, he can run through you, he can counter, he’s showing all of it off. He still has a long way to go. He’s going to be a good football player in this league. It may not come this year, but you could see it through practice that this kid, once he gets it, it’s going to be special.”

If nothing else, Williams quickly proved comfortable in his transition off the field. Over the summer, he asked offensive tackle Trent Williams if he could borrow his private jet to fly to Cabo San Lucas, Mexico, for a vacation. It was an audacious ask that Trent Williams declined (he was already using it at the time) but Mykel Williams stands by the request.

“My pops told me a while ago, man, closed mouths don’t get fed,” Williams said, laughing.

While Williams was sorting out his summer vacation plans, Collins spent a chunk of his time away from the team working to get healthy after a calf injury kept him on the sidelines in the spring.

Listed at 6-foot-6, 332 pounds, the Niners used a second-round pick on Collins with the idea that he could become the type of run plugging tackle who can take on multiple blockers and keep the linebackers free to make plays.

Because Collins missed those reps in the spring, it put him, as Saleh said, “behind the eight ball” when training camp began. That has been especially evident in one-on-one pass rush drills where Collins’ power can’t overwhelm NFL blockers like it did in college, where he had seven sacks in 64 games for the Longhorns.

There have been signs of progress as Collins has found ways to disengage from blockers, but he still has a long way to go to add more pass rush moves to his bag. Perhaps most important, Collins will always be working to keep his pads as low as possible.

Collins’ primary task will be helping San Francisco’s run defense return to form. With Collins on the field, the Longhorns allowed only 2.95 yards per rush attempt over the past two seasons.

“He’s a big body with good feet,” Saleh said. “Those are things you can’t teach. It’s just a matter of time before he gets his legs underneath him and he starts to make more of an impact. That’s visible.”

What’s also been visible is that West could prove to be the best bargain from this draft class after the Niners used pick No. 113 on him in April.

Since 2021, West was the only player in FBS with at least 50 quarterback pressures and at least 50 run stops. Still, his lack of size and a deep tackle class left him on the board when the Niners picked in the fourth round.

West wasted no time making an impact in training camp, regularly drawing a crowd to watch him work in one-on-ones. There, his combination of power and quickness jumps off the field. Starting right guard Dominick Puni was on the wrong end of one of those jarring bull rushes early in camp and said it “stunned” him as West knocked him backward and blew past for the win.

Saleh said West has “done a really nice job,” and though he still has footwork, hand placement and other details to clean up, West will “be part of the NFL for a while.”

For his part, West said he is trying new things to figure out how he fits in the NFL and in this scheme while trying to prepare for what could be a big role right away. With Kevin Givens out because of a pectoral injury, West has found himself running with the starters in recent practices.

“This is not like college,” West said. “You don’t get a redshirt year when you come in. You need to be ready to play. And I was always told pressure is never given, it’s earned. We feel like we earn that pressure and we’re going to do everything we can to continue to break those barriers.”

While there’s still a long way to go for all of the Niners’ prized rookies on the defensive line, they appreciate that they have one another to lean on. Collins said the trio is constantly asking one another questions and gathering information from the vets in the room they can pass to each other.

Saleh’s hope is that the time spent in the deep end of the pool now will allow his young trio of linemen to swim freely as the season goes on.

“The expectation for these rookies is that they show great growth and get better every day,” Saleh said. “They’re going to have splash plays in between. They’re going to have hair-pulling moments, but as long as they’re focused, you feel like their intent day-to-day is good, they’re taking care of their bodies, and they’re studying and preparing every day like a professional, you trust that they’ll grow and get better every day.”