MINNEAPOLIS -- Mitch Garver's breakout in his age-28 season was fueled by his willingness to think aggressively and change his game accordingly. He's already looking ahead to 2020 with that same attitude to continue to evolve his game.

Garver said at TwinsFest over the weekend that he has modified his offseason routine to focus on taking fewer swings before Spring Training while also emphasizing his approach against off-speed pitches. The hope is that he can more slowly build himself up to hitting to better prepare his body for the rigors of a full season while mentally addressing an area of potential offensive improvement.

"I'm a great fastball hitter," Garver said. "Everybody now knows that. We're trying to get ahead of the curve. Now, I'm switching things up. I'm looking for the off-speed."

Indeed, Garver slugged an otherworldly .838 against fastballs last season and hit 25 of his 31 homers off heaters, compared to slugging percentages of .395 against breaking balls and .261 against off-speed pitches.

He went on to say that he's been focused on hitting a different kind of off-speed pitch every day, with the goal of better recognizing such pitches out of the hand and also figuring out how to put his body in the best position to do damage on such pitches without sacrificing his ability to get on the fastball.

The other side of that offseason preparation for Garver is in getting his body ready for whatever manager Rocco Baldelli will demand of him this coming season, which is an area where Garver himself still doesn't have much clarity. Last season, Garver (73 starts) and Opening Day starter Jason Castro (72 starts) just about evenly split time behind the plate, while Garver also made four appearances as designated hitter and one at first base, hitting .273/.365/.630 in 93 games.

Garver said that he hopes to play in 100 games this season, with the assumption that he'll receive the bulk of the starts behind the plate. He said that there had been some discussion of moving him to first base for around 100 at-bats, but isn't sure how that will be impacted by the Josh Donaldson signing, which makes Miguel Sanó the primary first baseman and Marwin Gonzalez a solid backup at the position.

"I'll be ready for [first base]," Garver said. "We have so many versatile players with Marwin and [Ehire Adrianza] and Sanó and [Willians] Astudillo. There's maybe not a ton of at-bats there, but there could be some, so I need to be ready to slide in if necessary."

Even if that doesn't work out, Garver said that he quickly learned to appreciate Baldelli's approach to rest and recovery for his catchers last season and trusts the coaching staff to deploy him effectively.

"I got a taste of the magic recipe last year," Garver said. "At first, you're like, 'I feel really good.' And of course, it's May. 'I feel really good and I can play every day.' But by the time you get to August and September, it's like, 'My legs are dying right now.' You think back, and you're like, 'OK, it's good that we built up this rest over time.'"

Throughout Garver's surprise '19 campaign during which he won the American League Silver Slugger Award and set club records for homers and slugging percentage as a catcher, he was open about the fact that he was at the forefront of the so-called "launch angle revolution" -- that is, actively trying to hit the ball in the air -- while opening his lower half to more effectively drive the ball.

His aggressive defensive work last offseason was also paramount to his success. Following his '18 rookie campaign during which he was rated one of the worst receivers in the game, Garver worked with since-departed Minor League catching coordinator Tanner Swanson on new receiving techniques, including going down to one knee, in an effort to address that deficiency. In doing so, he improved from minus-9 framing runs in '18 to minus-3 in '19.

All that's to say: Garver set a precedent for targeted improvement through his offseason work, and after he saw those efforts pay off last year, he's hungry for more.

"I want to stay with my path and stay with my swing and be a good player," Garver said. "Like I said last year, I want to be a force in the lineup and continue to put up good numbers and just give our team a chance to succeed and win. And then on the defensive side, I want to continue to grow in that aspect and never reach a ceiling and continue to reach for it."