The San Francisco 49ers got early contributions from their 2025 draft class, which heavily focused on the defensive side of the ball.
After letting several veterans walk in free agency last offseason, the 49ers gave key roles to their top draft picks early in the season. Rookie defensive linemen Mykel Williams and Alfred Collins became starters and key contributors up front. Third-round pick Upton Stout won the starting nickel job. Day 3 picks CJ West and Marques Sigle saw early playing time. And
seventh-rounder Connor Colby even had a few starts at left guard.
Each of their rookie seasons went in different ways. We saw considerable growth from Williams through his first 11 games, both as a run defender and a pass rusher, before a torn ACL took away the second half of his rookie season.
Collins and West were both thrust into bigger roles at defensive tackle, and the 49ers run defense improved over the second half of the year when both were on the field.
Stout arguably was San Francisco’s most impactful defender in the secondary over the second half of the season after some major growing pains to start the year. And both Sigle and Colby went through those early ups and downs before being reserves for the latter half of the year.
The defense will have a new man at the helm in 2026, as Raheem Morris will replace the departing Robert Saleh as defensive coordinator, which could lead to some changes. Saleh had a tough task in 2025, dealing with a young defensive unit that saw its fair share of struggles, but also some optimism for the future.
This past weekend, Saleh sat down with NBC Bay Area’s Matt Maiocco and shared his thoughts on the 49ers rookie defensive linemen from last season, including one player who surprised him the most.
“It’s a shame Mykel’s season got cut short. Really excited for C.J. West and his development, even Alfred,” Saleh said, via Maiocco. “Like Alfred, I know he was a second-round pick and all, but he’s still probably the biggest surprise to me in terms of just how much better he got from training camp.”
“As the season went on, I really think he’s going to be special. His mindset to get better, his work ethic, he’s only going to get better. And when it triggers for him, he’s going to be a bear to stop.”
Collins is expected to start alongside newcomer Osa Odighizuwa at defensive tackle this season, while West should have a meaningful role once again. With Odighizuwa in the fold and Nick Bosa back from injury, the 49ers will hope to improve on a pass rush that ranked dead last in sacks last season.
But for that to happen, they’ll also need continued development from Collins, Williams, and West in Year 2.
