San Francisco 49ers rookie Nick Bosa suffered a low-grade hamstring strain last week. The team announced last Thursday that the defensive end would miss the next few weeks because of the injury. That means Bosa will miss the remainder of organized team activities, which conclude next week, and will likely miss the 49ers' three-day mandatory minicamp, scheduled to kick off on June 11.

The next time Bosa hits the practice field might be during training camp in late-July. The injury is just part of a long list of ailing players this offseason. Wednesday was the only practice open to the media this week. Fifteen players, including Bosa, sat out the session due to injuries, according to NBC Sports Bay Area.

Just because players like Bosa aren't on the practice field, it doesn't mean they have time off. Defensive line coach Kris Kocurek told reporters on Wednesday that the rookie will continue his work in the classroom and explained how he is taking advantage of OTAs while sidelined.

"Right now, it's mentally, and then trying to get back healthy and all that stuff," Kocurek said. "But he needs to get as many mental reps as he possibly can. Watching the other guys, it's sometimes hard when a guy gets nicked up and stuff and he has to watch from the sideline to realistically try to put himself in the play, but that's what he has to do right now because he can't go out there physically until he gets a little bit better.

"So, every mental rep that he can get, put yourself in the play from the play call, try to get him the play call, he knows what it is, he sees the formation, sees where he would line up, get on his keys, and see how he would react to the situation like he was in there.

"And then a bunch of work behind closed doors in the film room, getting with him on the board, watching practice, watching some of my stuff from previous years, watching some of the guys, studying them as much as we can. As much mental work as he can possibly get right now, we're utilizing."

The film study will involve players Kocurek has coached over the years. The assistant spent time with the Miami Dolphins and Detroit Lions before joining the 49ers in January. Kocurek said he has Bosa watching film on players like defensive end Ezekiel Ansah and going back to former defensive end Kyle Vanden Bosch, both of whom he coached in Detroit.

"We've watched a lot of [Vanden Bosch]," Kocurek added. "Just different guys that do different things that correlate to his skill set."

Bosa missed most of his final season with Ohio State after suffering a core muscle injury. He opted to undergo surgery to repair the damage and forego the remainder of the 2018 season to prepare for the draft. Bosa is over eight months removed from the last time he stepped on the football field for a game. The plan was already to ease him back into action and this injury has postponed his progress a bit.

"I think he'll be able to get back pretty quickly," Kocurek shared. "He comes from a Big Ten school that's a high level of competition. He's been at a high level of competition basically his entire life, so I think once we get him back in there, he'll integrate back in and be just fine."

Defensive coordinator Robert Saleh doesn't seem concerned about Bosa falling behind either. He was asked what the rookie is missing out on while sidelined.

"Just overall reps," Saleh responded. "For him, you'd love for him to be out there just so he can go through and get his reps. For those guys, maybe I underscore the D-line every once in a while, but it's just the mindset and all that stuff that he's missing, just get his legs under him. He hasn't played football in a year. To get his sea legs back, if you will. That's what I feel like he's missing, but I'm not worried about him being able to catch up."

You can watch Kocurek's media session below, courtesy of the Santa Rosa Press Democrat's Grant Cohn.