The San Francisco 49ers arrived in Australia expecting the unusual travel schedule to be the biggest complication of their Week 1 preparation. Instead, they will open the season without a starting defensive tackle they expected to rely on all year. Head coach Kyle Shanahan confirmed that Alfred Collins tore his patellar tendon during practice in Melbourne and will miss the entire 2026 season.
The timing makes the injury especially damaging. San Francisco is days away from facing the Los Angeles Rams at the Melbourne Cricket Ground in the first regular-season NFL game in Australia. Collins was injured after the team had already traveled across the Pacific, leaving the 49ers with little time to absorb the loss before a divisional opener against a Rams offense that can force an interior front to defend both the run and the pocket.
This is also a material change from the situation FSN examined in its earlier look at San Francisco’s preparation for the historic Australia opener. That story was about logistics, routine and how a veteran team would handle an extraordinary week. Collins’ injury changes the football problem itself.
What happened to Alfred Collins
Reuters reported that Collins suffered the injury during training in Melbourne and that Shanahan identified it as a torn patellar tendon. NBC Sports also reported the season-ending diagnosis. Patellar tendon injuries are significant because the tendon connects the kneecap to the shin and plays a major role in extending the knee; for the 49ers, the only immediate fact that matters competitively is the one Shanahan already supplied: Collins will not return this season.
Collins, 24, was a second-round pick in the 2025 NFL Draft and played in all 16 games as a rookie. He entered 2026 positioned for a larger role on the interior, making the injury a loss of both current production and expected development. San Francisco did not lose a late-roster reserve. It lost a young starter at the point in the calendar when teams have the fewest clean replacement options.
The 49ers were already dealing with defensive-line attrition
The Collins injury does not occur in isolation. Reuters reported that defensive end Sam Okuayinonu also suffered a broken foot over the weekend. That compounds the pressure on a front that entered Week 1 trying to get several pieces healthy and coordinated at the same time.
The immediate interior options include Osa Odighizuwa, CJ West, Gracen Halton and James Thompson Jr. NBC Sports noted that Halton was limited with an ankle issue while Thompson missed practice with a hamstring problem. That means the 49ers are not simply choosing between a full collection of healthy backups. They are sorting through a depth chart that already has availability questions while preparing for a divisional opponent.
West or Halton could be asked to start next to Odighizuwa. The exact snap distribution can still change before kickoff, but the strategic problem is obvious: San Francisco has to replace Collins’ expected early-down and interior work without creating a second weakness by overextending another player.
Why losing an interior defender matters against the Rams
Interior defensive line losses can be less visible than injuries to quarterbacks, receivers or edge rushers, but they change how a defense survives down after down. A reliable tackle can keep linebackers clean against the run, compress the pocket when the quarterback steps up and absorb double teams that create better matchups elsewhere.
Against the Rams, that work matters because Sean McVay’s offense is built to punish structural weakness. If the 49ers need to devote extra bodies to stabilize the interior against the run, they can make the coverage picture easier. If they stay light in the box and the replacement group cannot hold up, Los Angeles can stay ahead of the chains and keep the full playbook available.
San Francisco still has star talent capable of changing the game from the edge. Nick Bosa is returning from his own ACL recovery and has been working on a limited basis. But an edge rusher is most dangerous when the interior prevents a quarterback from simply climbing away from pressure. Collins’ absence therefore affects more than one position on the depth chart.
CJ West and Gracen Halton suddenly matter much more
The easiest replacement story is to name the next player on the depth chart. The harder reality is that replacing Collins will probably require a rotation. West has an opportunity to take a substantial share of the role, while Halton can become more important if his ankle allows it. Thompson’s hamstring status also bears watching because every unavailable body narrows the 49ers’ ability to keep the interior fresh.
That rotation has to be functional immediately. There is no preseason runway left and no normal home week to install a new plan. The 49ers are operating from Melbourne with a compressed calendar and an opponent that knows their personnel extremely well. A new starter will not get the luxury of easing into the job against a nonconference team with unfamiliar tendencies.
The injury adds pressure to San Francisco’s veteran core
One theme of the 49ers‘ Australia preparation has been the value of veteran stability. That becomes more important now. Fred Warner and the rest of the defensive communication structure have to help make sure a reshuffled front does not turn into alignment errors or poor run fits. The 49ers cannot replace Collins’ physical traits in a few practices, but they can reduce the secondary damage by being precise.
The same is true for Shanahan’s offensive approach. One way to protect a thinner defense is to avoid giving the Rams short fields and repeated extra possessions. San Francisco’s offense was already under pressure to start cleanly in an unusual environment. The loss of Collins makes ball security, third-down conversion and field position even more important.
What comes next for the 49ers
San Francisco’s first task is to finalize the rotation for the Rams game. The next is much larger: determine whether the current roster can cover Collins’ absence for an entire season or whether the front office needs to pursue outside help. September options rarely match the quality of the player a team expected to start, so any acquisition would likely be about stabilizing depth rather than finding a one-for-one replacement.
For Week 1, the standard is simpler. The 49ers need West, Halton and the rest of the available interior group to keep the defense structurally sound long enough for Bosa, Warner and the secondary to make impact plays. If the replacements can do that, San Francisco can survive the immediate shock.
The larger loss will remain. Collins was supposed to spend 2026 developing into a long-term piece of the 49ers’ defensive front. Instead, his season is over before the opener. A history-making week in Melbourne now carries a very different football story: San Francisco must prove that the depth beneath one of its young starters is good enough to prevent a devastating injury from becoming a season-defining weakness.