Will The Strong UDFA Showings Be Sticky?
Did we uncover any gems in preseason week 1?
It is a tall task to crack the 49ers’ 53-man roster as an undrafted free agent. We saw that last week when training camp standout Isaiah Nayor was (perhaps mistakenly) let go. In 2024, they carried former UDFAs Kevin Givens and Robert Beal Jr. on the defensive line into the regular season, and also got 12 games out of Evan Anderson, mostly on special teams. Givens in particular has provided much-needed quality depth over the years.
It’s important to remember that in Week 1 of the preseason, these are reps often taken against players who will be selling cell phone covers in mall kiosks by September. We don’t want to get too far ahead of ourselves. That being said, you would hope to see flashes from these guys given those circumstances. We did, on more than one occasion.
Defense
Derrick Canteen (S) and Jakob Robinson (CB):
To get Robinson out of the way quickly; he had one solid tackle for loss in the game on 36 snaps. There was nothing else particularly noteworthy, and with the quality veteran depth ahead of him, it would be surprising if he were in serious contention for a roster spot.
Derrick Canteen, on the other hand, led the defense with 66 snaps, amassing five tackles and earning the team-leading PFF tackle grade. Safety is far more wide open, and it will be interesting to see if he gets as many reps in Week 2.
Stone “Cold” Blanton (LB):
Blanton was a mixed bag. His big highlight of the evening was an excellent punch-out on a rushing attempt. However, he was also credited with the most missed tackles in the game (three) and drew an average PFF grade. The coaching staff seems to love him. He’s been singled out more than once during training camp and it feels like he’s firmly in the competition for one of the last linebacker spots. Still, he has his work cut out for him.
Sebastian Valdez (DT):
Lastly for the defensive side, and by far the best UDFA showing of the evening: Sebastian Valdez. Valdez only took 32 snaps but made them count—posting four total tackles (two solo, one for loss) and adding another QB pressure. It was hard to miss how often he put his offensive counterpart on the back foot and disrupted rushing lanes. He kept his eyes up and, even when losing some reps initially, recovered and rallied to the ball.
This is a player who started 13 games for Washington last season, posting 49 tackles, 4.5 tackles for loss, two sacks, and a pass deflection. While his explosiveness and size leave some to be desired, his overall composite and agility grades in the draft were in the class’ upper echelon, leading to a Relative Athletic Score (RAS) of 9.27. The man benched 225 pounds 34 times. Had he been drafted, would have been the top mark in the class.
It translated against Denver. I’m extremely bullish on his profile as an athlete, size notwithstanding. But there’s a real question of how he’ll fare when he can’t bully lower-tier competition with sheer physical power. Time will tell, but look for him to get more work in Week 2. He earned it, and at a minimum seems to be a strong practice squad candidate.
Offense
Corey Kiner (RB):
Kiner is an interesting prospect. Even in a loaded draft class, PFF loved him. He forced 81 missed tackles in 2024 and averaged 4.12 yards after contact per attempt—both metrics highly predictive of NFL success. At just 5'9", he drew an elusiveness rating of 161.9, second in the class by a wide margin over the rest, and behind only Ashton Jeanty’s all-time outlier of 215.1.
He was the 49ers’ fifth-highest graded offensive player against Denver, scoring a 65.9 on 34 snaps, producing 45 yards on 10 carries, and forcing his fair share of missed tackles. He kept a low center of gravity and was difficult to bring down on first contact.
This running back room is wide open. Mason and Mitchell are gone, Abdullah is on season-ending IR, Isaac Guerendo won’t play until September, and Jordan James is recovering from finger surgery. The only other serious or even just warm, living bodies are the steady but unremarkable Patrick Taylor Jr. and the shadow of what was once Jeff Wilson Jr. Still, barring a big display in the coming weeks, Kiner seems likely to end up as a practice squad piece at best for now. There are too many entrenched names ahead of him. In the meantime, he’s a fun watch for the next week or two.
Drew Moss (RG):
Drew Moss is a name I want to keep bringing up as the roster gets fleshed out. He took 29 snaps in Week 1 and scored the second-highest offensive grade on the team (77.3), behind only Connor Colby (77.8)—his direct competition for a roster spot. Moss was also the highest-graded pass blocker at 83.7.
I won’t repeat everything from our preseason Week 1 standouts coverage, but Moss is an elite athlete in terms of quickness at guard. His ability to work sideline-to-sideline and downhill on a variety of assignments was evident both in college and in his first 49ers snaps.
Guard is much deeper than tackle for San Francisco, with Ben Bartch, Connor Colby, Dominic Puni, and Nick Zakelj all in the mix. However, Moss moved all over the line in college and played mostly at tackle. That versatility could provide an edge in maximizing roster utility come September. I’ll be watching closely to see how reps are distributed against the Raiders, and whether projected starter Bartch’s 46.3 run-blocking grade improves.
Moss making the roster, or even the practice squad, is far from a sure thing, but offensive line depth has been an ongoing issue throughout Shanahan’s tenure. Every rostered lineman has a shot to make the final cut. The battle between Colby and Moss will be a tight, competitive one to watch in the coming weeks.