49ers' Nick Bosa reportedly expected to miss 'a few weeks' after pulling calf during practice

Injuries have been a thorn in Nick Bosa 's side, and the latest is reportedly expected to sideline him for "a few weeks."

The five-time Pro Bowl defensive end pulled his calf during Thursday's practice and is now out, including for Sunday's Week 3 game against the Arizona Cardinals , ESPN's Adam Schefter and NFL Network's Ian Rapoport reported Friday.

San Francisco is reportedly weighing whether Bosa needs to be placed on injured reserve. If he goes on IR, he'll have to miss a minimum of four games.

Bosa, 28, played in only three games last season. He tore his right ACL in Week 3 of the 2025 campaign versus the Cardinals. That marked the third ACL tear of his football career.

He also suffered a left ACL tear in 2020, in Week 2 of his second season in the league.

With two season-ending injuries already disrupting his NFL career, it was up in the air if Bosa would return in time for this season's opener, what turned out to be the Niners' 27-7 beatdown of the Los Angeles Rams in Melbourne, Australia . The former NFL Defensive Rookie of the Year (2019) and Defensive Player of the Year (2022) suited up Down Under and turned in four total tackles, registering a pair of tackles for a loss in the process. By the time San Francisco's 35-13 victory over the Miami Dolphins wrapped in Week 2, he was tied for the team lead with six pressures, according to Next Gen Stats.

It wasn't unusual for Bosa to sit out Wednesday's practice, the team's first practice of the week, given his veteran status and injury history. At the time, he was listed as a nonparticipant, with the designation of "resting player/knee." But on Thursday, a day on which the Niners added "calf" next to his name on the team's injury report, he reportedly joined the 49ers ' battalion of injured personnel.

Although San Francisco is 2-0, it is once again dealing with a rash of recovering players. The 49ers' defensive line is navigating several absences. Defensive tackle C.J. West landed on IR with a knee issue this week. During the first two weeks of the season, defensive end Sam Okuayinonu and defensive tackle Alfred Collins were lost to IR, too, because of foot and patellar tendon injuries, respectively, that they picked up in practice.

Plus, a high ankle sprain is keeping defensive tackle James Thompson Jr. out three-to-six weeks. And there's no guarantee edge rusher Romello Height plays Sunday against the Cardinals, as he's weathering a broken hand and hasn't practiced so far this week .

That list doesn't even include defensive end Mykel Williams , whom the 49ers selected 11th overall in last year's draft. Like Bosa, a torn ACL threw a wrench in his 2025 season. He's still on the physically unable-to-perform list and isn't eligible to return to game action until San Francisco's Week 5 matchup versus the Seattle Seahawks .

Additionally, the 49ers are juggling a batch of wide receiver injuries .