Matt Vierling swung at a down-and-in slider with three balls, two strikes and two outs in the bottom of the ninth inning Sunday at Comerica Park. As the ball jumped toward the left-center seats, he flipped his bat in celebration and watched the ball fly 409 feet for a walk-off home run.

The numbers from the Detroit Tigers' 14-11 victory Sunday over the Toronto Blue Jays were eye-popping enough.

It was the first walk-off homer of Vierling's career in his 332nd game, amid his fourth MLB season. The clutch homer ended a three-hour, 19-minute marathon, which included 25 runs, 31 hits and seven home runs between the Tigers and Blue Jays. Two of those home runs, and four of the runs driven in, belonged to Vierling in the sixth and ninth innings.

But what Vierling said after the big moment was telling.

"I'm just happy that all the boys are fired up," Vierling said, "and we got a win and a series win."

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That's Vierling.

A team-first player, always doing what's best for the group.

A do-it-all player, hungry to thrive in his utility role.

A kind human being, someone people want to be around.

"I see Matt in the offseason," said Mason Horne, Vierling's coach at Christian Brothers College High School in St. Louis, Missouri. "The kid hasn't changed. He's the same guy I remember as a 15-year-old freshman. He's obviously a lot bigger, but he's the same guy."

"He's really genuine in his desire to get to know people and connect with people," said Mik Aoki, Vierling's college coach at Notre Dame. "That's not a phony baloney thing. That's what he is. He's a really good listener. He's a thoughtful person. I think he's got a high level of emotional intelligence. He's a (expletive) great guy, great kid."

His former coaches — Horne in high school and Aoki in college — have watched Vierling's development over the past dozen years, both up close and from afar.

Vierling is one of seven Tigers with at least 150 plate appearances this season. The 27-year-old ranks fourth among that group with a 117 OPS+, meaning his production on offense is 17% above league average. He doesn't draw a lot of walks, but he puts the ball in play, rarely chases pitches outside the zone and limits strikeouts.

Vierling has always hit the ball hard — his average exit velocity this season of 92.2 mph is in MLBs 89th percentile —but he's finally starting to unlock his power potential. The secret is turning on inside pitches and getting the ball in the air to left, something he did twice in Sunday's win. He is a successful swing adjustment away from evolving into an everyday player capable of hitting 20-plus homers per season.

Then again, that has been the narrative for his entire professional career. So what has changed?

Vierling has been trying to perfect a new movement with his hands since the end of last season.

"I worked on this load with my hands that really helped," Vierling said, "and also being super early and ready, loading up really early. ... Getting movement in my hands before I swing is really beneficial for me. I feel like I need a little momentum, and that coincides with loading early."

Glove work

Vierling has played 151 games for the Philadelphia Phillies (2021-22) and 181 games for the Tigers (2023-24), with just 23 home runs total. (In January 2023, the Phillies traded Vierling, infielder Nick Maton and catcher Donny Sands to the Tigers for left-handed reliever Gregory Soto and infielder Kody Clemens.)

Along with his work at the plate, Vierling has been busy in the field: In his second season with the Tigers, he has started 35 games and come off the bench 12 times while bouncing between third base and the outfield on defense.

"I've learned playing in the big leagues that I can help the team in a lot of different ways," Vierling said. "I've also learned you got to adapt to help the team in whatever way you can. I've honestly had to do that my whole life."

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Vierling spent the entire offseason preparing to be the primary third baseman, only to transition back to the outfield when the Tigers signed veteran third baseman Gio Urshela in spring training. When Urshela missed a few weeks with an injury, Vierling handled a majority of the workload at third base, but when Urshela returned from the injured list earlier this month, Vierling went back to the outfield again.

Two years ago, Vierling played center field for the Phillies in the World Series.

"I never thought I'd be playing third base in the big leagues," Vierling said, "or starting at second base, or first base. I never thought I'd do that. I feel like I've been pretty good at being able to do that stuff. It makes me think of myself more as a player, like I can do a bunch of things that can help the team win."

Changing positions is nothing new.

Vierling, a three-sport athlete in high school, grew up as a pitcher and shortstop, but when he made the varsity team as a freshman, Horne moved him from shortstop to the outfield. He was a better pitcher than hitter as a freshman, so switching from the infield to the outfield protected his arm and showcased his speed.

"As a 15-year-old kid, he was at first a little hesitant, just because he had never played the outfield," Horne said, "but he took to it really well and didn't put up a fight. It was my job to get him to buy in, one way or the other. I tried to get him to understand that it's what's best for him and what's best for the group."

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He transitioned back to shortstop for his senior year, playing up the middle alongside his younger brother, Mark, at second base. The brothers won Missouri's Class 5-A championship in 2015.

The elder Vierling showed up at Notre Dame for his freshman season in 2016, and before he stepped on the field, he transitioned from shortstop to outfield again. By 2018, his final year of college — similar to his path as a senior in high school — Vierling spent more time in the infield than the outfield, locking down third base.

In three years at Notre Dame, Vierling played center, right, and left, as well as third and first base. He also pitched 26⅓ innings in 26 relief appearances, including five innings in his final year.

His fastball sat in the 93-94 mph range.

"I don't think Matt relished being on the mound, but he knew we needed it, so he did it," Aoki said. "College players really get their nose bent out of shape in their draft years because this is what they've been trying to pursue, and they get all wrapped up in themselves a lot of times. Not all the time, but a lot of times. This idea of 'draft-itis,' it's real, but that wasn't the road Matt was going down. That's just not who he is."

The Phillies selected Vierling in the fifth round, at No. 137 overall, in 2018.

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It has been nearly six years since Vierling stepped into the world of professional baseball, a long way from St. Louis and South Bend.

He made his MLB debut for the Phillies in June 2021, and, again, the same versatility has come up over and over.

Vierling has played almost everywhere on the field, getting reps at all three outfield positions and three of four infield positions. He hasn't played shortstop, but the Phillies instructed him to take ground balls there in warmups in case of an emergency.

That do-everything nature has extended to the lineup, as well: Vierling has started at least one game at every spot in the batting order. (He checked off the final box — the cleanup spot — in the third week of May with the Tigers.)

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Pulling ahead

Recently, Vierling has gotten the ball in the air to the pull side with more consistency.

It's been the missing piece of his game.

To get there, Vierling worked on the load of his swing — studying Miguel Cabrera's mechanics and talking to the future Hall of Famer about timing — throughout last season. He felt comfortable with new hand movements for the first time Sept. 7 against New York Yankees left-hander Carlos Rodón. Since then, his pull rate has increased from 31.2% to 40.3% and his fly-ball rate has increased from 30.8% to 43.3%.

As a result of the adjustment, Vierling's .815 OPS since Sept. 7 ranks 29th among 134 qualified position players (and 11th among 51 qualified outfielders, ahead of teammates Kerry Carpenter and Mark Canha).

He's had more success, but he hasn't turned into a player who asks for more playing time or a permanent position.

"I don't think I can be like that," Vierling said. "I know my role here is to help the team in the infield and the outfield. It's just better for me to play all these positions and help the team. That's what makes the team better."

Vierling is a team-first player.

Always has been, always will be.

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' Matt Vierling finding final piece of his swing