The San Francisco 49ers gained a new gauge of what their 2025 roster looks like Saturday. Even after taking the 30-9 loss to the Denver Broncos in their NFL Preseason opener.
Kyle Shanahan rested his veteran starters from Brock Purdy, to Nick Bosa, to George Kittle. All three won't worry about their starting spots becoming in danger. As the trio plays a pivotal part in what the 49ers do on gamedays.
However, it's different for two other first stringers. San Francisco witnessed two stellar performances out of some newcomers. Rookies who immediately look like threats to alter the two deep.
And place these two veterans on the hot seat in the process.
Malik Mustapha pushed by 49ers rookie

Mustapha is listed on the PUP (physically unable to perform) list. He likely wasn't going to suit up Saturday anyway.
But a 2025 day three selection stole the free safety spotlight in his absence.
Fifth-rounder Marques Sigle impressed inside Levi's Stadium. He piled seven tackles and impressed in the open field. Sigle delivered a strong nose for the football. Leaving one 49ers fan to believe John Lynch just drafted another new fifth round gem.
Marques Sigle might be another 5th round 💎 pic.twitter.com/L4BMZ7wXWO
— Coach Yac 🗣 (@Coach_Yac) August 10, 2025
The fifth round has become a money round for S.F. and the general manager. Kittle came via the fifth in the 2017 NFL Draft class. Talanoa Hufanga (who signed with the Broncos in the offseason) came from that round. Cornerback Deommodore Lenoir is another from that round who rose to starter and new CB1.
Sigle likely would've crossed 10 tackles if it weren't for a knee bruise.
Shanahan raved about Sigle's performance. Revealing it became a continuation of an impressive week in Santa Clara from the former Kansas State Wildcat.
“I thought he was one of the guys who flashed a lot tonight… It was a few days into camp when he really got going, but he’s had a hell of a week here and finished it off good today,” Shanahan shared.
Sigle shared via S.F. Standard 49ers insider David Lombardi what his mindset was before his league debut.
“It comes down to film study and being confident in playing fast, regardless of if you mess up or not,” Sigle said. “That was the biggest thing in my mind, regardless of good play, bad play — I'm always doing the next play, so I'm just going to play fast every play.”
But Sigle's outing is the first warning for Mustapha. He's already expected to miss the start of the 49ers season with his lingering knee injury. Sigle could look in the free safety spot even if Mustapha is healthy. The 5-foot-11, 200-pounder looked Hufanga-like on the field.
Another injured 49ers starter could lose ground to rookie

Kevin Givens entered training camp facing a push from C.J. West. The Indiana trench star just complicated things off his impressive Saturday outing.
The '25 draft pick clogged gaps for the 49ers interior. West displayed his powerful strength by splitting this double team.
CJ West (@CJWEST50) stays in his gap vs a combo block. West splits it & has to be held from making the play. He does bottle up the RB though & allow for others to rally! #StopTheRun #49ers #FTTB pic.twitter.com/XanYdvIo5k
— DLineVids (@dlinevids1) August 10, 2025
West didn't deliver a single quarterback pressure. But he penetrated through the line of scrimmage like he still had “IU” on his helmet.
The interior defender galvanized a Hoosiers defense that sparked a stunning College Football Playoff run. West disrupted gaps off foot quickness and a violent upper body.
He admitted there were humbling moments as the game progressed. Which he shared to Tim Kawakami of the S.F. Standard.
I'm going into it just playing as hard as I possibly can — and knowing that as a rookie, you're going to get humbled,” West said.
“And it was very humbling today kinda going against the starting line on another team. ‘Cause there's a lot of other stuff you have to learn and other stuff you have to do still to become better,” West said.
He added he noticed that offensive linemen are “smarter and faster” compared to what he saw in his college career. But joked, “they know different ways to cheat the game just a little bit to kinda give themselves the advantage.”
West still impressed with his strength and tenacity. The 6-foot-1, 315-pound defender looks like he wants more than a spot on the two-deep.
He's coming for Givens' spot if Saturday was any indication. The veteran is anticipated to miss portions of 2025 anyway with a pectoral injury. But like Mustapha, Givens teeters toward becoming a veteran losing ground to a rookie.
West brings flashbacks of D.J. Jones — who became lauded for plugging running lanes despite his smaller stature. Jones starred from 2017 to 2021 before leaving for the Broncos. West rises as the new “Jones” for defensive coordinator Robert Saleh and Shanahan.