San Francisco 49ers head coach Kyle Shanahan spoke with reporters after Tuesday's practice and provided several injury updates.
Wide receiver Brandon Aiyuk was among several players who left practice on Sunday with an injury. He was running a deep route down the right sideline, pulled up, grabbing at his left hamstring, and headed to the sideline, where he remained for the remainder of practice.
Shanahan said an MRI revealed a mild hamstring strain, and Aiyuk is week-to-week.
Defensive end Nick Bosa has not practiced since last Friday. He has missed three practices since then. Shanahan said that an MRI revealed a muscle strain in his leg, and he is week-to-week.
Defensive end Dee Ford left for the sideline on Sunday after one 1-on-1 rep against tackle Mike McGlinchey. He suffered a calf irritation and is day-to-day.
Running back Raheem Mostert was among those who did not practice on Tuesday. He received a veteran day off.
Shanahan also provided an update on wide receiver Deebo Samuel, who is rehabbing from a Jones fracture suffered in June. The coach remains hopeful the second-year player will be available for Week 1, but nothing is certain at this point.