SANTA CLARA – Fight after fight broke out within minutes of the 49ers’ joint practice with the Titans, jeopardizing just how much longer Tuesday’s work might last.

Order was restored, practice lasted about another 90 minutes, and the 49ers’ starters got in enough work that most will sit out tonight’s 6 p.m. preseason opener at Levi’s Stadium.

“There won’t be many starters playing,” coach Kyle Shanahan said. “That doesn’t mean none, but we’ve got to balance that out.”

The Titans, coached by former 49ers defensive coordinator Robert Saleh, are expected to play their would-be first-stringers.

The 49ers, as usual, have injury issues to navigate, but they also are not a youth-laden outfit desperate for game reps before their regular-season opener, four weeks from today against the Los Angeles Rams in Melbourne, Australia.

Quarterback Brock Purdy has not played in a preseason opener since his 2022 rookie year — and surely everyone recalls his one touchdown on three completions that signaled he’d be the next franchise QB. He played only the second preseason game last year, with cameos in the final two in 2023 and ’24, “just try to have that mindset of getting ready for a game, getting in pads, getting hit,” Purdy said. “But also, you want to be smart and safe and get to the regular season healthy.”

In that spirit, don’t expect to see superstars such as Christian McCaffrey, Mike Evans, Trent Williams, Fred Warner, Dre Greenlaw or Nick Bosa.

Benefiting most from these three preseason games should be their 19 draft picks over the past two years, and all seem fit enough to suit up except defensive end Mykel Williams (knee; Physically Unable to Perform list) and running backs Jordan James (rib) and Kaelon Black (adductor).

Here are five players to watch against the Titans:

DEFENSIVE END ROMELLO HEIGHT

Height, a third-round pick, has spent most of his first training camp lining up as a first-string defensive end opposite Sam Okuayinonu. And Height is their most exciting addition to a pass rush that still seems woefully understaffed.

In Tuesday’s joint practice, Height got pressure on Titans quarterback Cam Ward, but Ward also slipped past his overpursuit once. With Bosa yet to practice in team drills all camp and sidelined the past week with knee tendinitis amid his ACL comeback, the 49ers need to accelerate Height’s participation.

Otherwise, they must hope a gem emerges from this camp’s injury fill-ins: Titus Leo, Ogbo Okoronkwo and Quinton Bell, who appeared to sustain an ankle injury Tuesday. Also worth watching is fifth-round pick Jaden Dugger’s potential pass rush from the “fever” linebacker spot created to provide versatility and unpredictability.

WIDE RECEIVER JORDAN WATKINS 

Sure, everyone should want to see top draft pick De’Zhaun Stribling debut in the wide receiver corps, provided he suits up tonight. However, his roster spot is locked, so there’s much more mystery over which wide receiver can moonlight as a punt returner. Watkins may need to prove capable in all regards, after an injury-slowed rookie year that produced two catches in four games with all 25 snaps on offense (none on special teams).

Watkins’ camp has been mixed, with a nice catch offset later by a misaligned route or inability to body up on a contested catch. One competitor as a receiver/returner parted Wednesday with the release of Junior Bergen, a 2025 seventh-round practice squad player. Jacob Cowing’s bid to reclaim that role from 2024 has been paused by a hip injury.

LINEBACKER NICK MARTIN

Missed tackles in last year’s preseason debut were a harbinger of Martin’s lost rookie season. He played 15 defensive snaps before a Nov. 30, season-ending concussion. This camp, however, Martin isn’t overrunning as many plays and is getting shots at weak- and strong-side linebacker.

“He’s a football-padded, I’m-wearing-pads type of guy,” linebacker coach K.J. Wright said. “He got sexy quickly: He strikes, he’s fast, he’s physical. At times I have to tell Nick, ‘Just slow down! Don’t hit Christian hard.’ When he sees the ball, he just finds a way to get to it. So you guys will see come Thursday how explosive he is and how much better he’s gotten from Year 1 to Year 2.”

QUARTERBACK KURTIS ROURKE

Rourke’s last game was a College Football Playoff loss at Notre Dame in December 2024, when he played on a torn ACL throughout that season with Indiana after five previous years at Ohio. Rourke spent his 49ers rookie year rehabbing from ACL repair, and he’s rotated with Adrian Martinez for QB3 reps behind Brock Purdy and Mac Jones.

Rourke’s final pass of Tuesday’s joint practice got intercepted, but his 6-foot-4, strong-armed frame definitely offers a different look to investigate in the preseason.

GUARD CONNOR COLBY

Coaches insist an open competition remains at left guard, seemingly the only vacancy on the offense’s starting lineup. Colby opened camp on the first string but has been usurped the past week by veteran Rob Jones, whose violent streak showed up well in Tuesday’s action against the Titans.

Analyzing guards in a preseason game is a chore, so at least keep an eye on who’s getting action there. Shanahan mentioned he’d also like to see rookie Carver Willis get some snaps.

ROSTER MOVES

Running back Zamir White signed a one-year deal as the 49ers likely won’t play McCaffrey, Black and James for the preseason opener. Also signed were cornerback Eli Apple and Xavier Thomas.

Australian rookie punter Jack Bouwmeester was waived two weeks into a camp competition with left-footed Corliss Waitman. Defensive end K.J. Henry was waived with an injury settlement.