SANTA CLARA (CBS SF) — San Francisco 49ers top draft pick Nick Bosa will miss the remainder of the preseason after suffering a high ankle sprain in practice, team officials announced on Thursday.

Bosa will sit out the entire pre-season and hopefully be ready for the 49ers regular season opener on Sept. 8th against the Tampa Bay Bucs.

“I believe there are three components of a high ankle sprain, which makes it an official high ankle sprain. He does not have all three of them,” head coach Kyle Shanahan said. “That’s all the science I know on that. Basically, it’s a minor high ankle sprain, but there’s no such thing as a minor high ankle sprain, because we know those are a much bigger deal than low ones. We’re hoping for Week 1.”

Team GM John Lynch said the rookie out of Ohio State had been impressive at training camp, terming him ‘a game changer,’ before he went down during a practice season on Wednesday.

“We’re going to be very prudent,” Lynch told KNBR listeners. “The great thing I can tell you about Nick Bosa, is he’s been dominating practice out here on a daily basis.”

Bosa saw his final season with the Buckeyes shortened by injuries to just three games. But over that span, the 6-4, 266-pounder showed the impact he can have collecting 14 tackles, six tackles for loss, 4.0 sacks, two fumble recoveries and one forced fumble.

“He’s a game-changing type player,” Lynch told the radio station. “Everything we hoped and expected. We have to get him right for this season.”

The injury came on the same day that Defensive Coordinator Robert Saleh spoke enthusiastically about Bosa’s play to reporters.

“He’s been progressing very well,” he said. “I’m very pleased with him. He’s got a knack for pass rush, he’s been very good in the run game. So, at this point he’s progressing very well and we’re all very excited about him.”