SANTA CLARA, Calif. -- One day before the San Francisco 49ers' first training camp practice, quarterback Jimmy Garoppolo has been cleared to fully participate.

"It's officially official," Garoppolo said. "We're good to go."

Garoppolo returns after a lengthy rehab from the torn left anterior cruciate ligament he suffered in a Sept. 23 loss to the Kansas City Chiefs. He missed the final 13 games of last season and spent much of the offseason working his way back.

Now, Garoppolo can move forward with no restrictions and will resume his role as the team's starting quarterback when the Niners begin practice on Saturday morning.

According to coach Kyle Shanahan, Garoppolo will have no limitations in practice, including the amount of repetitions in team drills.

"Full go, he was doing 7-on-7 for all the OTAs, so he's been pumped to get an offensive line in front of him and a defensive line," Shanahan said. "So he's more than ready to go."

The only current stop sign for Garoppolo is the Aug. 10 preseason opener against the Dallas Cowboys, a game Shanahan ruled him out of on Friday.

In the spring, Garoppolo was able to participate in organized team activities on a limited basis, skipping out on team drills but taking reps in 7-on-7 and individual passing drills.

When the Niners wrapped their offseason program, Garoppolo was mostly through with the rehab portion of his recovery and spent most of the past six weeks working on performance-related training with noted quarterback guru Tom House in Southern California.

"I'm really happy where I'm at," Garoppolo said. "I think it was a very successful summer. I got a lot done, a lot of different things we wanted to work on and it's really coming together. Now it's time to roll."

Garoppolo plans to continue to wear the titanium knee brace he started wearing in the spring. The next step will be getting acclimated to having defenders in his face and around his legs as he throws.

"I think all those things will just happen kind of naturally," Garoppolo said. "In practice, we try to make it as game-like as possible. Those moments, it's just a matter of time until they happen. When they do, I think we'll approach it and see how it goes."

Garoppolo is entering his second full season as San Francisco's starting quarterback and the second year of a five-year, $137.5 million contract. It's an important season for the Niners and Garoppolo, who still hasn't had the opportunity to prove himself over the course of a 16-game slate.

While Garoppolo acknowledges the outside expectations for him, he said he always feels like he has something to prove.

"I hold myself to a pretty high standard, so I'm always pushing myself [on], 'How can I get better?'" Garoppolo said. "What are my weak spots that I can improve on and things like that. That's just the game. You've got to love that part of it."

Like Garoppolo, cornerback Jason Verrett (Achilles) and linebacker Kwon Alexander (knee) have been cleared to go, though both will be monitored in camp. Shanahan has also ruled Alexander out of the exhibition opener.

Elsewhere on the injury front, the 49ers will open training camp with four players -- center Weston Richburg (knee), running back Jerick McKinnon (knee), tight end Garrett Celek (back/concussion) and safety Jimmie Ward (collarbone) -- on the physically unable to perform list.

From that group, only McKinnon comes as a mild surprise as he, too, is recovering from a torn ACL. Niners general manager John Lynch said McKinnon had "a little flare-up" in his knee recently but the expectation is that he will be back relatively soon. For Ward, the aim is to have him back the week of the Aug. 19 preseason game and preceding joint practices against the Denver Broncos, which is a similar time frame to the hope for McKinnon.

The Niners plan to bring Richburg along slowly but have him ready for the Sept. 8 opener against the Tampa Bay Buccaneers.

According to Lynch, Celek has the longest road ahead of him as he recovers from back surgery. Lynch said Celek is unlikely to return in time for the start of the season and is a candidate to start the regular season on the in-season version of the PUP list.