Steelers vs. Bills Preseason Finale: Defensive Line and Roster Bubble Battles to Watch Thursday at Highmark Stadium

San Francisco and Las Vegas close out the preseason slate Thursday night at Allegiant Stadium, with kickoff set for 8 p.m. ET. It’s the final tune-up before both teams cut down to a 53-man roster, and for dozens of players on both sidelines, this is the last opportunity to make an impression before final decisions get made this weekend. Coverage is local only — KPIX CBS 5 for Bay Area viewers and FOX5 Las Vegas for the home crowd — with NFL+ streaming the game everywhere else.

Both the 49ers and Raiders enter the night at 1-1 in the preseason. San Francisco is coming off a lopsided 41-17 win over the Los Angeles Chargers, though that result says little about who actually plays extended snaps Thursday, since neither team is expected to lean on its established starters.

What’s Actually at Stake

San Francisco head coach Kyle Shanahan summed up his roster picture bluntly this week, calling it “extremely fluid all the way up to the cutdown,” a fair description for a team dealing with more than 20 players in some stage of injury recovery. The 49ers still haven’t settled their starting left guard job, and the competition for the second safety spot next to Ji’Ayir Brown remains open. Malik Mustapha was the presumed favorite there before a hamstring injury slowed him, allowing Marques Sigle to take the lead for now. Third linebacker is another spot in flux, with Sigle also involved in that mix depending on how the safety competition shakes out.

San Francisco’s most-watched competition is at quarterback, not for the starting job — Brock Purdy has that locked down and won’t play Thursday — but for the No. 3 spot behind Mac Jones. Kurtis Rourke, a 2025 seventh-round pick who spent last season recovering from a torn ACL, has generally been sharper than fellow reserve Adrian Martinez in camp and preseason action, though a rib injury has him questionable for the finale.

Las Vegas Has a Real Quarterback Decision to Make

The Raiders’ situation carries more weight leaguewide. Kirk Cousins is viewed as the likely Week 1 starter after taking the majority of first-team snaps, but Klint Kubiak has refused to name him outright, repeatedly stressing that competition remains open at every position. Rookie Fernando Mendoza, the top overall pick in this year’s draft, has shown flashes of the traits that made him a coveted prospect, but he also had an inconsistent Week 2 outing. That’s created an opening for veteran Aidan O’Connell, who sparked a 19-0 second-half comeback against Houston last week. With some outside roster projections having Las Vegas keep only two quarterbacks, O’Connell may be playing for his roster spot Thursday night.

Defensively, the Raiders appear closer to resolving their cornerback competition opposite Eric Stokes. Darien Porter has taken the bulk of first-team reps over the past two weeks and was pulled early from last week’s game against Houston after just 10 defensive snaps, while rookies Hezekiah Masses and Jermod McCoy played far more — often a signal that a coaching staff already views a job as settled. Cornerback depth behind that trio remains a live question, with Greedy Vance reportedly making a push after a strong recent practice stretch.

Prediction and Best Bet

With both rosters leaning on backups and roster-bubble players for the majority of snaps, expect a choppier, lower-continuity game than a typical NFL broadcast. Las Vegas’ backup quarterback group has more preseason reps and recent success to lean on, which should be the deciding factor in a tight finish at home.

• Prediction: Raiders 23, 49ers 20
• Best Bet: Under the total

Two offenses relying heavily on backups and roster hopefuls, combined with defenses rotating in players fighting for their NFL futures, tends to produce sloppier execution and fewer sustained scoring drives, making the under the more logical lean for Thursday’s finale.