Lynch said veteran pass rusher Dee Ford, whom the 49ers traded for in March, is close to returning but fans shouldn't expect to see him during the preseason.
"Dee is very close," Lynch said. "I don't think we'll see Dee in the preseason, but we're alright with that. He just had kind of a chronic tendinitis issue that flared up again. We wanted it gone for the regular season. They've done a really good job. It's good to see him out here. He's out here running now. He's doing really well with that."
Running back Jerick McKinnon briefly returned after a lengthy rehab from an ACL injury sustained before last season. He had a flare-up in his knee and received platelet-rich plasma injections earlier this month.
"McKinnon, that's something that's been a fluid situation," Lynch said. "We're just trying to be very judicious. Last time, I don't think we rushed him when he had his flare-up, but it didn't work. So you go back and say, 'What can we do better this time to give him the best possible chance?' We're trying to do that, but I think that should be soon."
Then you have rookie defensive end Nick Bosa, who suffered an ankle injury on August 7 and hasn't practiced since then. Cornerback Jason Verrett left the same practice, also with an ankle injury.
"Nick Bosa, he's coming along really well," Lynch said. "I think truly, (getting him back for) Week 1, I don't know, 50-50, but it's going to be touch and go as to whether he makes it. And Verrett, the same way. But we'll learn a lot more.
Lynch also discussed the team's offensive line. They thought the unit had better depth heading into the upcoming season before swing tackle Shon Coleman was lost for the year with a fractured fibula and dislocated ankle.
The offensive line did get back two guards, Mike Person and Joshua Garnett, this week.
"Josh Garnett, the good news is he's been back out at practice, albeit in a cast, this week," Lynch said. "Josh is going to have to come show us that he's ready to compete."
Weston Richburg, the 49ers' starting center, remains on the Active/Physically Unable to Perform list after undergoing knee surgery in January.
"Richburg is doing really well in his rehab," Lynch said. "The plan is to have him back, hopefully, to practice around Chargers week, going into next week. That's going to be a welcome sight. He's a really good player we invested heavily in, and it's going to be nice to see him back and healthy. His rehab has gone extremely well."
Lynch added, "We're starting to get guys back, and that's a good thing."