Here's how the 49ers' touted rookie D-linemen look so far at training camp

The dog days of August are here. The 49ers have been practicing for about a week and a half. On Saturday, they'll wrap up their second block featuring pads. The preseason opener against Denver, which will be preceded by a joint practice with the Broncos, is a week away.

"I think we're all excited for Denver to get in here," 49ers defensive coordinator Robert Saleh said Friday, "so we can just see our guys face different people, different schemes, and different blocking combinations."

It'll be a chance for the 49ers to finally bust out a proper measuring stick for a project deserving of intensive progress reports. That's the team's huge reconstruction of the defensive line outside of star Nick Bosa. The 49ers feature six new players in that room — four rookies (Mykel Williams, Alfred Collins, CJ West, and Sebastian Valdez), a trade acquisition (Bryce Huff) and a recent signee (Jaylon Allen).

So what's the initial feedback on the 49ers' four rookie D-linemen at this early point in the process?

The defensive tackle, a fourth-round selection, has wowed onlookers the most. West stole the show on Monday, when the 49ers first donned pads and conducted one-on-one drills. West dominated all five of his matchups, including one against second-year guard Dominick Puni — who played at a high level as a rookie.

West helped transform Indiana's run defense in 2024, so there was little question about the 320-pounder's strength. But the explosiveness that West has paired with that power has enabled him to regularly slide offensive linemen backward on the bull rush.

"He's done a really nice job," Saleh said of West. "He's getting better every day. A lot of things he still has to clean up with footwork, hand placement, and all that. But he's one that we're excited about. He’s going to continue to get better every single day. He'll be part of the NFL for a while.”

There might have been some outside consternation when Williams missed a practice this week with an ankle issue, because a high ankle sprain had dogged him throughout the entire 2024 season at Georgia. But Williams was back at practice the very next day.

How has Williams looked?

Let's refer to the top expert opinion on this matter. That's left tackle Trent Williams, a future Hall of Famer who saw himself destabilized on a pair of pass-blocking reps against the rookie during camp's first padded practice. The left tackle seems like a source close to the matter.

“Mykel is a huge dude, man,” he said. “You generally don’t see guys that size on the edge. It sucks having to base block guys whose arms are long as your legs, but I think he has a chance to be a really good player in the NFL.

“I think he has a chance to be dominant. He has the best coach in the league coaching him. Gets to learn from some of the best, from obviously Nick. I'm happy to see how he turns out. I think he has all the tools to be an All-Pro.”

The 49ers' second-round pick has not looked nearly as comfortable as West and Williams through this first stretch of camp.

It's worth noting that Collins is the tallest of the bunch — he's over 6-foot-5 with a wingspan that's over seven feet long — and therefore faces the steepest challenge in developing the body control needed for the NFL game. So much of line play at this level hinges on establishing leverage with a low center of gravity, and tall D-linemen — especially tackles, who face shorter interior O-linemen — usually must work to consistently deliver proper technique.

“He's coming along," Saleh said of Collins. "He missed all of OTAs — not to make excuses for the young man, but he did. It was with an injury, so it wasn't like he was camping out doing D-line drills. He was just trying to get up to speed. So, he's behind the eight ball, but he's working hard.

"Love the way he's approaching every day, and he'll catch up. He's a big body with good feet. 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.”

The good news is that Collins, with his 332-pound frame, has already looked very hard to move. He's undoubtedly a block gobbler. So that's his floor. But the 49ers, considering they spent a second-round pick here, would like a higher pass-rushing ceiling — which will require more explosion off the snap — from Collins.

Bosa himself isn't worried.

“Both Mykel and Alfred are coming from different styles, so they're learning different techniques and different aim points," Bosa said. "But both have immense talent.”

The defensive tackle, listed at 301 pounds, features a robust base. His strength has been evident in one-on-one drills, during which Valdez has generated noticeable pushback against O-linemen.

Valdez was a four-year standout at Montana State before transferring to Washington for his final season of college ball. He signed with the 49ers as an undrafted free agent. This is a team that needs interior pass-rushing juice, so Valdez has a shot.

"He's done a good job to this point," Saleh said. "With these three preseason games coming up, he's going to have more opportunities to show what's real and what isn't.”