The Detroit Tigers believe in Carson Kelly.

Kelly, an eight-year MLB veteran, is returning to the Tigers in 2024 after his $3.5 million club option was picked up by president of baseball operations Scott Harris at the beginning of the offseason. The 29-year-old spent the final six weeks with the Tigers in the 2023 campaign after getting released by the Arizona Diamondbacks in mid-August.

His offseason program is a continuation of the adjustments the Tigers asked him to make on offense and defense.

"I loved my time there for six weeks or so, and I'm very excited to be back," Kelly said. "I think it's a great organization. I think you see the upcoming young guys, and hopefully, I can be a piece of that to win games and grow these young guys to compete and the best version of ourselves."

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On offense, the Tigers want Kelly to increase his bat speed and find consistency in the movement of his swing. On defense, the Tigers want him to focus on a one-knee setup to improve his ability to steal strikes at the bottom of the zone.

Kelly hit .206 with two home runs, 14 walks and 40 strikeouts over 50 games in 2023: 32 with the Diamondbacks and 18 with the Tigers. With Detroit, he hit .173 with one home run, seven walks and 17 strikeouts. As a catcher, Kelly received above-average marks in blocks above average and caught stealing above average, but he was below average in framing runs.

The numbers, though, don't tell the full story.

"Sometimes, it takes time for these adjustments to translate to performance," Harris said Nov. 7 at the general manager meetings. "Sometimes, it takes a few months. Sometimes, it takes a full offseason. ... We're confident, after a really good offseason, that he can show up to Lakeland (for spring training) and help us win. That's why we picked up the option."

Kelly, who learned to be an elite game-caller under the guidance of former St. Louis Cardinals catcher Yadier Molina, worked on the offensive and defensive adjustments upon joining the Tigers, especially behind the scenes with the coaching staff, but the work-in-progress adjustments weren't always evident in games.

It's easier to instill adjustments in the offseason without the requirement of competing in games.

"A lot of it was framing for catching with a different stance," Kelly said. "We hammered that as much as possible. For hitting, I was finding a good rhythm and finding where I was breaking down in the movements of the swing. It's hard to do that in six weeks, but we have a really good plan for this offseason."

The Tigers believe Kelly can tap into his power of old to complement his contact skills and strike zone discipline. The prescribed adjustments: cleaning up his swing mechanics and boosting his bat speed.

A series of injuries, most recently a right forearm fracture in March, led to inconsistent mechanics. That contributed to a decline in power. After breaking his forearm, he wasn't cleared to start his rehab assignment until the beginning of June.

"I was so focused on the forearm that I lost track of other things," Kelly said. "We got to compete and put ourselves in the best position to succeed, but those three or four months that I worked in the offseason got put on the back burner because I was focused on my arm. I didn't get to swing a bat for two months, three months. Coming back, it was a quick ramp-up period. I didn't have the same flexibility that I had prior to the injury. That was a big hindrance to me."

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His average exit velocity dropped from 88.9 mph in 2019 to 86.8 mph in 2023. He hit 36 home runs over 248 games in 2019-21, then just nine homers over 154 games in 2023-23.

But Kelly had three of his seven extra-base hits in 2023 during his final 11 games.

"We're doing a swing speed program," Kelly said. "A lot of it is not hitting baseballs. I'm hitting heavier plyo balls. It's the size of a baseball, but it's a heavier weighted ball. What that does is put me in a position where I can't hit it with my arms. I have to use my entire body with my movements. That's one thing that we're working on."

On defense, the Tiger believe Kelly can improve his receiving skills, thus stealing more strikes, to complement his strong and accurate throwing arm. The prescribed adjustment: Switching from a crouch to a one-knee setup.

His 45.9% strike rate ranked 36th and his minus-1 framing runs tied for 34th among 61 catchers with at least 1,000 pitches called. Starting catcher Jake Rogers, who called more than 2,700 pitches, ranked top-15 in both categories.

"I've dabbled with it, but I've never been a full-time one-knee catcher," Kelly said. "As I get a little bit older and see the benefits, it makes me want to do it. I'm like, 'Why didn't I do this five years ago?' But this is something I have to do every single day. Over time, I'm going to get there."

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His 54.9% strike rate on pitches above the strike zone ranked 11th among the group of 61 catchers, but his 50.5% strike rate on pitches below the strike zone ranked 29th. He struggled with his framing around three of the four corners of the zone, as well.

Still, Kelly has been an above-average pitch framer in the past with the Diamondbacks.

"It's for stealing strikes at the bottom of the zone, and I'm already in a better position to block," Kelly said. "I think it allows you to do a better job of being able to get under that low pitch and then also staying on that up pitch. It just puts me in a better position to react to wherever the ball is. We like to think pitchers throw to every edge of the plate, but the reality is, they miss. Being in a strong position to adjust to those misses, do my best to receive those and present that to the umpire, I think going to one knee is the way to go."

Game-calling is the main reason why the Tigers were willing to pick up Kelly's option — despite the need for adjustments on offense and defense . He prides himself on guiding pitchers through a game.

His work there stood out to the Tigers in four games with rookie right-hander Sawyer Gipson-Long in September. In those four games, Gipson-Long posted a 2.70 ERA with eight walks and 26 strikeouts across 20 innings.

It starts with understanding the scouting reports for individual pitchers and individual hitters.

"Living and dying with them, being prepared and almost knowing more than they know in certain situations," Kelly said. "Then, you earn that trust from them. We got a lot of guys with really good stuff and also some craftsmen. I love that part of the game."

Kelly lives in Portland, Oregon, during the offseason and is spending his time at two nearby facilities: ROKKE Performance Therapy and The Yard Baseball Academy (owed by EForce Performance). He trains under former MLB catcher Kory Casto and works out with Baltimore Orioles catcher Adley Rutschman.

And Kelly is obsessed with making adjustments to get better.

"It's been really good," Kelly said. "I've fallen in love with the process. I feel like it's important every single year to fall in love with that process. Being in that process will generate results."

Contact Evan Petzold at epetzold@freepress.com or follow him @EvanPetzold.

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This article originally appeared on Detroit Free Press: Detroit Tigers catcher Carson Kelly has plenty of offseason homework