49ers rule Bosa out for preseason with 'significant' injury

Rookie defensive end Nick Bosa is out for the preseason with a "significant" ankle injury, San Francisco 49ers general manager John Lynch said. In a radio interview with KNBR on Thursday, Lynch said there are "elements" of a high ankle sprain. The team ran a series of tests on Wednesday as Bosa joined a growing list of injured defensive linemen, all unavailable for Saturday's preseason opener against the Dallas Cowboys.

Bosa got tangled up in a mass of humanity during a drill at Wednesday's practice. Lynch said a "big human being" fell on Bosa's ankle and caused the injury. The No. 2 pick in the 2019 NFL Draft, Bosa will aim for the Sept. 8 regular-season opener against the Tampa Bay Buccaneers as his targeted return date, Lynch said.

Bosa's four-year deal includes a fifth-year option and is worth $33.5 million before the option year. He played only three games at Ohio State last season as a junior due to a core muscle injury before declaring for the NFL draft. The 21-year-old suffered a Grade-1 hamstring strain in May and was limited much of the offseason.