SANTA CLARA, Calif. -- San Francisco 49ers defensive end Nick Bosa suffered a calf injury in practice Thursday that is expected to cost him a few weeks, sources told ESPN's Adam Schefter and NFL Network's Ian Rapoport on Friday. Bosa will not play in Sunday's game against the Arizona Cardinals as the 49ers work to determine whether the five-time Pro Bowler needs to be placed on injured reserve, sources said. The 49ers are leaning toward not placing Bosa on injured reserve in part because they are running out of IR spaces, a source told Schefter.

Returning to start the season from a torn ACL in his right knee, Bosa had played 70 snaps in the first two weeks combined. He was preparing to play against Arizona in a Week 3 that would have been almost exactly a year since he tore his ACL against the Cardinals.

Bosa's injury is the latest and perhaps biggest hit to a ravaged 49ers defensive line. The Niners placed defensive tackle C.J. West (knee) on injured reserve this week and have lost defensive end Sam Okuayinonu (foot) and tackle Alfred Collins (patellar tendon) to IR from injuries suffered in practice the first two weeks.

Without Bosa, the 49ers' healthy and available defensive ends are Keion White, Khalid Kareem and Ogbo Okoronkwo. Another defensive end, Mykel Williams, is on the physically unable to perform list. He is expected to return to practice next week from a torn ACL suffered last season but can't play in a game until Week 5 when the 49ers visit the Seattle Seahawks.