The San Francisco 49ers placed running back Isaac Guerendo on the reserve/physically unable to perform list, ESPN's Jeremy Fowler reported Sunday. Guerendo, who suffered a torn pectoral muscle while lifting weights in late May, will automatically miss at least the first four games of the season,
Guerendo underwent surgery and spent training camp on the active/PUP list, but now it looks as though his timeline to return to practice will have to wait.
Had he been healthy, Guerendo would have entered the season as the 49ers' fourth running back, behind Christian McCaffrey, Jordan James and third-round rookie Kaelon Black. San Francisco used its 2026 draft capital on Black specifically to add competition in the backfield, and James took over as the No.
2 option once camp opened. Guerendo, a fourth-round pick in 2024, was already fighting for a roster spot before the injury. His placement on PUP buys him time to heal without immediately costing the 49ers a roster spot, since players on reserve/PUP don't count against the 53-man limit.
Guerendo has appeared in 30 career games for San Francisco, rushing for 420 yards and four touchdowns on 5.0 yards per carry, with his most extensive workload coming as a rookie during a stretch when McCaffrey was out with injuries. He was limited to special-teams duty for most of 2025, finishing that season without a carry.
With Guerendo out to open the year, the 49ers' running back room behind McCaffrey now runs through James and Black. Guerendo won't be eligible to return to the 53-man roster until at least Week 5, assuming he's healthy enough by then and San Francisco chooses to activate him.
This article originally appeared on Niners Wire: 49ers place former 4th-round pick on reserve/PUP to begin 2026 season
