49ers DE Bosa (hamstring) out until training camp

San Francisco 49ers top rookie Nick Bosa will sit out the rest of organized team activities due to a Grade 1 hamstring strain, the team announced Thursday.

The 49ers have three weeks of OTAs left and then will break for a month before training camp gets underway in July.

Bosa, drafted second overall in April, pulled up and limped off during one-on-one drills Tuesday, the second day of practices involving both rookies and veterans. He remained on the sideline through the end of practice to watch.

Before getting hurt, Bosa had worked primarily with the second-team defense in 11-on-11 drills.

The 21-year-old played in only three games as junior last season at Ohio State, suffering a core muscle injury in September and sitting out the remainder of the season to recover and prepare for the draft.

Bosa became the fourth first-round pick in his family last month, joining brother Joey Bosa (No. 3 in 2016) of the Chargers, father John Bosa (16th in 1987) and uncle Eric Kumerow (16th in 1988) of the Dolphins.

--Field Level Media