Rookie defensive lineman Nick Bosa injured his right hamstring during Tuesday’s organized team activity.
49ers coach Kyle Shanahan confirmed the injury but was uncertain of the severity, Matt Maiocco of NBCSportsBayArea.com reports.
Bosa, the No. 2 overall pick, pulled up during pass-rushing drills and walked off with a slight limp. He did not finish practice or take part in a conditioning run at the end of practice.
Bosa’s injury history was something of a concern for some NFL scouts during the pre-draft process. He played only three games last season at Ohio State after injuring a core muscle and underwent surgery on both sides to repair torn muscles.
He also tore an ACL in high school.