The 11 Most Important 49ers to Watch in the Preseason Game vs. Denver

The 49ers will play their preseason debut against the Denver Broncos tonight at 5:30 p.m. Pacific. And although the result of the game won't matter, individual performances will, because some of these backups will have to play at some point during the regular season, and we need to know which ones the 49ers can count on.

Here are the most important 49ers to watch:

Quarterback Mac Jones

He's having an outstanding camp, but will his performance carry over to live action? Brock Purdy isn't having a particularly great camp -- he has thrown eight interceptions in 12 games -- but he's a gamer. We've seen what he can do in the face of a real pass rush when the games count. What will Jones do under pressure? Will he be calm and poised like he is in practice, or will he panic? Has he lost his confidence for good, or has Kyle Shanahan's system reinvigorated him? We've seen Trey Lance and Shedeur Sanders put together some impressive moments in preseason so far. I wouldn't be surprised if Jones does the same.

Left tackle Spencer Burford

Sep 9, 2024; Santa Clara, California, USA; San Francisco 49ers offensive tackle Spencer Burford (74) watches the action from the sideline in the third quarter against the New York Jets at Levi's Stadium. Mandatory Credit: David Gonzales-Imagn Images | David Gonzales-Imagn Images

Since the 49ers traded for Trent Williams, they're 4-12 when he doesn't play. That's because he's their best run blocker and best pass protector. When he plays, he can impose their will on the ground to his side. When he's out, the 49ers don't run the ball well, which makes them one-dimensional, and they don't have the offensive line, the quarterback or the system to win without a dominant running game.

Which brings us to Burford. He was a guard for the past three seasons. Now, he is Williams' backup. Can he hold his own against the Broncos backups tonight? Because theoretically, Burford will have to play at left tackle at some point this season. Williams hasn't played a full season since 2013.

Guard Connor Colby

Mar 2, 2025; Indianapolis, IN, USA; Iowa offensive lineman Connor Colby (OL06) during the 2025 NFL Combine at Lucas Oil Stadium. Mandatory Credit: Kirby Lee-Imagn Images | Kirby Lee-Imagn Images

The starting left guard is Ben Bartch, who gets injured frequently. So his backup is important, and it currently is Nick Zakelj, who's built more like a center than a guard. He's not big. They could really use rookie guard Connor Colby to assert himself.

Running back Corey Kiner

The can't burn out Christian McCaffrey in the first two months of the season. They have to conserve him so they have him when Brandon Aiyuk returns. That's when they could make a real run. Which means they need a good backup running back. And Isaac Guerendo and Jordan James are injured. So the door is wide open for undrafted rookie Corey Kiner to make the team if he plays well in the preseason. In practice, he runs hard and seems elusive.

Wide receiver Jordan Watkins

Aiyuk is out until midseason, Jauan Jennings has a calf injury and seems to be holding out for an extension, Jacob Cowing has a hamstring injury and Demarcus Robinson most likely will be suspended for the first few games. Which means Watkins could start at wide receiver Week 1 if he continues to play well. Look for Jones to target Watkins frequently. He's extremely fast and he's not afraid to run over the middle.

Wide receiver/returner Junior Bergen

Jul 24, 2025; Santa Clara, CA, USA; San Francisco 49ers wide receiver Junior Bergen (86) catches a pass during drills on the second day of training camp. Mandatory Credit: D. Ross Cameron-Imagn Images | D. Ross Cameron-Imagn Images

The 49ers drafted him to return kicks and punts, so let's see him do it. Is he really a good returner? If so, he'll be a weapon. If not, he can't make the team, because he's not good enough as a receiver to make it.

Cornerback Jakob Robinson

He's an undrafted rookie who's playing more like a fifth-round pick this offseason. He's built like a young Deommodore Lenoir and he plays like him, too. If he keeps breaking up passes in preseason games like he has in training camp, he'll make the team.

Nickelback Upton Stout

Jul 23, 2025; Santa Clara, CA, USA; San Francisco 49ers cornerback Upton Stout (20) runs a play during the first day of training camp at SAP Performance Facility. Mandatory Credit: D. Ross Cameron-Imagn Images | D. Ross Cameron-Imagn Images

He looked like the best nickelback on the field during the 49ers' joint practice with the Broncos two days ago -- even better than Broncos first-round pick Jahdae Barron. Granted, it was just one practice, but Stout has been rapidly improving all offseason. And he hasn't even tackled anyone yet. If you watch his highlights from college, most of them are big hits behind the line of scrimmage. He plays like a linebacker. I can't wait to see him in action.

Linebacker Nick Martin

May 9, 2025; Santa Clara, CA, USA; San Francisco 49ers third-round draft pick Nick Martin (45) works out with his teammates during the teamís rookie minicamp. Mandatory Credit: D. Ross Cameron-Imagn Images | D. Ross Cameron-Imagn Images

It's so difficult to assess linebackers in practice because players can't tackle. A linebacker's primary job is to tackle and be violent. That's why the 49ers drafted Martin. They also have Dee Winters, who makes plays in coverage, but he's not as good a run defender as they'd like. If Martin makes a few plays, he could take Winters' job.

Defensive Tackle Alfred Collins

Feb 27, 2025; Indianapolis, IN, USA; Texas defensive lineman Alfred Collins (DL08) participates in drills during the 2025 NFL Combine at Lucas Oil Stadium. Mandatory Credit: Kirby Lee-Imagn Images | Kirby Lee-Imagn Images

He has been one of the least impressive rookies in camp so far, but that doesn't mean he'll struggle tonight. We knew he'd be a work in progress as a pass rusher. The 49ers drafted him to anchor against double teams and stop the run. Tonight, we'll see if he can do those things. If he can, he's a good pick. If he can't, he's a bust. I think he can.

Defensive tackle CJ West

He has been one of the most impressive rookies in camp so far, but that doesn't mean he'll be a good player in the NFL. Lots of defensive tackles would look good if they were facing the 49ers' backup offensive linemen every day. If West dominates the Broncos' backups too, he just might be special.