49ers’ defensive line loses another: DT Alfred Collins sustains knee injury

MELBOURNE, Australia — Defensive tackle Alfred Collins sustained a season-ending knee injury in the 49ers’ practice Tuesday, further decimating an already suspect defensive line just ahead of Friday’s season opener here against the Los Angeles Rams.

Collins tore his patellar tendon during defensive warmups, coach Kyle Shanahan revealed before Wednesday’s practice at AAMI Park. The 2025 second-round pick heroically forced and recovered a goal-line fumble in last season’s overtime road win over the Rams.

“That is a big loss,” Shanahan said. “We lost two D-linemen pretty much for the year, after (53-man roster) cuts and before the first game, which is a huge challenge.”

The other casualty was defensive end Sam Okuayinonu, who fractured a foot in last Wednesday’s final practice before flying to Australia.

“It’s terrible, really unfortunate for him and Sam. Camp ends and those guys get those unlucky breaks and that stinks,” said Nick Bosa, who delcared himself 100% healthy and ready to launch his ACL comeback in Friday’s game.

“I texted (Collins) last night and let know there’s nothing anybody can say to you at that moment or really the entire process,” Bosa added. “Guys can tell you to keep your head up but they won’t be there for the surgery or the nine months you’re grinding by yourself to get back. He has to know there is a light at the end of the tunnel and I’ve told him I’ve been there a few times.”

The Rams will be without a defensive tackle of much higher caliber than Collins. They flew out Tuesday night without the recently unretired Aaron Donald.

As for the 49ers’ probable defensive front, second-year defensive tackle C.J. West likely will replace Collins and start next to Osa Odighizuwa at defensive tackle. Expected to start at defensive end are Bosa and likely Keion White, backed up by Romello Height and recent acquisition Khalid Kareem.

Ogba Okoronkwo is a candidate to come up from the practice squad, but the 49ers likely must use one of two such promotions on a defensive tackle.

Gracen Halton, who missed much of the past month with an ankle injury, is expected to rotate in, along with whoever is promoted from the practice squad between Sebastian Valdez and Kevin Givens. Valdez did not appear in a game last season as an undrafted rookie who mostly stayed on the practice squad; Givens has 14 starts in 70 games since 2019 with the 49ers.

James Thompson Jr., an undrafted rookie who made last week’s initial 53-man roster, was participating Wednesday after missing the previous two practices because of a hamstring strain. His availability and that of other 49ers will be officially announced a day before the opener.

Being so far from the U.S. hinders the 49ers’ options for adding last-minute replacements.

“Any D-lineman is a possibility, unless you can name some guys we can fly here real quick,” said Shanahan, who then appeased local reporters and half-jokingly said there were some Australian Football League players around here who might be worth a look.

Bosa practiced Tuesday for only the second time in the past month because of tendinitis in his surgically repaired right knee. He and tight end George Kittle (Achilles) are expected to play, albeit on a snap count. “Both look great but we have to be smart with that,” Shanahan said.

Both Kittle and Bosa were practicing Wednesday, as were all other projected starters.

Shanahan smiled at Wednesday’s other major news: that the Rams delayed launching Donald’s comeback. “I was preparing for the worst and glad we don’t have to see him this week,” Shanahan said.