SANTA CLARA, Calif. -- In the midst of a 2015 season that was statistically his worst since his rookie year, Atlanta Falcons quarterback Matt Ryan often found himself paying such close attention to offensive coordinator Kyle Shanahan's playcalls that he had little time to think about anything else.

Ryan had reached three Pro Bowls, but during his first year in Shanahan's offense, Ryan found a more involved scheme than anything he'd seen in his previous seven seasons. And the early returns in that offense were far from Ryan's standard: 18 touchdowns and 15 interceptions through 14 games.

Ryan said it wasn't until the final month that Shanahan's playcalls became second nature and he started to settle in. Over the final two weeks, he averaged 320 yards per game with three touchdowns and an interception.

"The biggest difference was just comfort level within that scheme," Ryan said. "Understanding the terminology. As a quarterback, your mind is thinking about a lot of different things when the playcall is coming in, you're having to think about down and distance, what personnel is coming in, guys are kind of hearing the call. When you don't have that automatically, it's hard to think about those other things. When you finally get comfortable where you're only kind of half listening to what the playcall is and you know it, that's when you can kind of focus on the things that are important at your position."

Armed with that understanding and a host of talented offensive options in his second full season under Shanahan, Ryan put together an MVP season, throwing for 4,944 yards and 38 touchdowns, as he led the Falcons to Super Bowl LI. It was the type of breakthrough performance that thrust Ryan into the discussion of the league's elite quarterbacks and made Shanahan one of the hottest coaching candidates on the market.

Shanahan went on to take over the San Francisco 49ers and is now hoping for a similar breakout season from quarterback Jimmy Garoppolo, who also happens to be entering what could be his second full season as the starter.

Both Ryan and then-Houston quarterback Matt Schaub made notable improvements in their second year operating Shanahan's offense, and expectations for Garoppolo are high even after a 2019 season that would be considered a success by any reasonable measure.

Although Garoppolo continues to be the target of outside criticism, his 16-game season as a starter was an unqualified success. He threw for 3,978 yards, fourth most in Niners history, and completed 69.1% of his passes, which ranked fifth in the NFL. His 102.0 passer rating ranked eighth. He also was the only quarterback in the league to finish in the top five in completion percentage, yards per attempt and passing touchdowns.

It came one season removed from a torn left ACL and resulted in the Niners going 13-3 and storming to an NFC championship and an appearance in Super Bowl LIV.

"He learned a lot and also played at a very high level," Shanahan said. "To be able to go through that this year, having very similar players around him, the offense doesn't change. You just get better at it. I think that'll definitely help him."

As Shanahan is quick to point out, Garoppolo should never feel more comfortable in the offense than he does now. Garoppolo has been with the team since October 2017, starting the final five games that season and three more in 2018 before the ACL tear.

That means Garoppolo has had plenty of time to make Shanahan's offense his own. He has had ample opportunity to watch tape of the likes of Ryan and Schaub, something Shanahan leaned on when Garoppolo first arrived. Shanahan used the tape to show Garoppolo and his fellow quarterbacks examples of what plays, footwork, route progressions and coverages should look like.

During Garoppolo's rehab at the end of the 2018 season, he spent time watching film with Shanahan's father, Mike. The ultimate goal? To help him understand how the run and pass tie together and the keys to making every offensive playcall look simultaneously similar and different.

"I think that's the magic of the offense," Garoppolo said. "Kyle does a great job with that, thinking a couple of plays ahead and putting you in a good situation. I think when we're thinking the same way and we're on the same page, that's when we're really clicking."

After slogging through the first half of last season coming off the knee injury, Garoppolo found himself playing much better down the stretch. Still, one problem lingered and is the obvious next step forward: cutting down on turnovers. Garoppolo threw 13 interceptions during the regular season (tied for eighth most in the NFL) and three more in the postseason. He also had a handful of other passes that could have been picked off but were dropped by defenders.

If everything else about Garoppolo's performance from 2019 stays the same and he can cut down on the turnovers, it would go a long way in silencing some of his detractors. Ryan more than halved his interceptions from 16 to seven in his second season under Shanahan.

Dan Orlovsky, ESPN analyst and former NFL quarterback, believes Shanahan's ability to scheme things open lends itself to creating a hyperaggressive approach in his quarterbacks. That approach comes with plenty of good but can also lead to more mistakes.

"As much as I love aggressive quarterback play, it can fool you into thinking everything is going to be there and you put the ball in harm's way a lot," Orlovsky said. "And there's a fine line between being super cautious with the ball and never putting it in harm's way. So, the No. 1 thing for me would be trying to play reactionary football more than assuming football. I thought [Garoppolo] probably had a handful of picks last year ... because he assumed the guy would be open. Kyle called this play, it's a sick play design, dude is gonna be open and all of a sudden you assume that guy is gonna be open rather than just playing reactionary and trusting your eyes."

If Garoppolo can indeed make that leap, it would help cement his status as the Niners' franchise quarterback. While general manager John Lynch said Sunday that Garoppolo is "as big a part of our plans as he's ever been," the team could theoretically move on from him after the season with less than $3 million in dead money and more than $24 million in savings.

It's highly unlikely things would go so wrong this season for that to happen, though. The more plausible scenario is Garoppolo earns a contract extension, but memories of his rough fourth quarter in the Super Bowl (3-for-11 for 36 yards with an interception and he overthrew receiver Emmanuel Sanders for a potential winning touchdown) still linger.

"Kyle demands a lot from his quarterbacks and we all know Jimmy's history," Lynch said. "Jimmy's come back and I think performed really well in camp. And we're excited. I just think more time in this system that's a very demanding one, and I think the history of quarterbacks of this system, it shows that, right around now is when they start hitting stride. ... We're excited to see where this goes."

ESPN Atlanta Falcons writer Vaughn McClure contributed to this story.