SANTA CLARA, Calif. -- Coming off a torn ACL that cost him most of the 2018 season, San Francisco 49ers quarterback Jimmy Garoppolo spent the ensuing offseason rehabilitating.

As he enters this offseason coming off a high right-ankle sprain that cost him 10 games, Garoppolo's objective isn't just getting back to 100%. It's also about figuring out how to stay that way.

"It's all about availability," Garoppolo said. "I know that. It's been a series of unfortunate events with the injuries and things like that, but one thing I'm excited about is just getting ready for this offseason. Getting the body back to where it needs to be, getting ready for next season."

As things stand, Garoppolo remains the 49ers' starting quarterback, according to coach Kyle Shanahan and general manager John Lynch. While the Niners have left a bit of wiggle room should an upgrade become available -- Deshaun Watson, anyone? -- it's still entirely possible, if not likely, that Garoppolo will be under center for the Niners to open the 2021 season. If that’s the case, expect the Niners to improve the options behind him with a quarterback selected relatively high in the draft, a veteran with starting experience or both.

For Garoppolo to remain the starting QB, he must first do whatever he can to stay on the field. Over the past three seasons, Garoppolo has missed 23 starts. Even before arriving in San Francisco, Garoppolo was unable to stay healthy in limited starting chances for the New England Patriots, as a sprained right shoulder cost him two potential starts in place of Tom Brady.

There's no common denominator between the injuries, and misfortune is undoubtedly a part of it, but Garoppolo intends to explore options that can prevent further issues and remove the injury-prone label.

"It was obviously a little bit of bad luck, but you can't associate everything with that," Garoppolo said. "I always try to look for new things for my body, new things to eat, new exercises, workout routines, whatever it is. So, I always try to mix things up in the offseason and try to find what works for me, but yeah, it'll be the same this offseason. Just try to get advice from people, talk to people, see what they've done in the past and it's a bunch of things coming together."

For Garoppolo, things have never quite come together. He was at the controls for the entire 2019 season as the 49ers surged to Super Bowl LIV. Garoppolo's second-half struggles in that game generated more questions about whether he could evolve into the quarterback the Niners need to get over the hump.

Shanahan and Lynch briefly kicked around the idea of signing Brady last offseason, though it never went anywhere and they didn't pursue the future Hall of Famer. The hope was that a second consecutive healthy season would allow Garoppolo to take the next step, similar to how Matt Ryan did in his second full season under Shanahan with the Atlanta Falcons.

That idea never took hold, as Garoppolo sprained his right ankle in the first half of Week 2 against the New York Jets. When he returned, by his own admission too early, in Week 5 against the Miami Dolphins, Garoppolo wasn't fully healed. In Week 8, he sprained the ankle again.

"We're encouraged, because when he saw the specialist and I think that was the hesitancy to put him back out there, that the severity of his second high ankle or reinjury led to, 'Hey, there is an option where he might have to have surgery,'" Lynch said. "We wanted to avoid that at all costs. We were able to do that."

All of which has created a surge of speculation the Niners could move on from Garoppolo. After all, they boast a roster capable of competing for Super Bowls, but that task is made nearly impossible with backup quarterbacks under center the majority of the time.

Despite that, Lynch and Shanahan have remained steadfast in their belief Garoppolo will return, albeit with the caveat they always look at every position for potential improvement.

With backups Nick Mullens (restricted) and C.J. Beathard set to hit free agency, the 49ers will have at least some turnover at the position this offseason. It stands to reason Garoppolo's injury history will force the Niners to invest more resources there, potentially drafting a long-term replacement with more upside than Garoppolo similar to the way the Kansas City Chiefs drafted Patrick Mahomes with Alex Smith on the roster.

In the meantime, the rumors will continue to swirl. As Garoppolo notes, that's part of the deal as a starting quarterback in the NFL.

"All those things get said, but at the end of the day, I'm a 49er," Garoppolo said. "I'm here to be the quarterback of this team, and every day I go out there and try to prove that to my teammates and my coaches. At the end of the day, that's what really matters.

"As far as next season, I go into the offseason, I'll make a list of goals for myself, whether it's work on my accuracy, work on intermediate throws, but the durability is No. 1 right now. We'll attack that, but then just as far as getting ready for next year, as long as the ankle's good, I think we'll be in a good spot."