CINCINNATI -- Drew Carlton expected to be serving as the opener for Triple-A Toledo on Saturday in Omaha. He hadn’t pitched in five days, and he had been making spot starts for the Mud Hens when their rotation has been short. Then, he was called into manager Tom Prince’s office.

“Prince is in there and all the other coaches, trainers, everybody’s in there,” Carlton said. “And Prince told me it’s his proudest moments when he gets to tell guys that they’re going to The Show.”

With that, one of the more unlikely stories of the Tigers' rebuild made his way to the big leagues. 

“I asked him on a scale of 1-10, 10 being the most shocked and surprised in his career,” manager A.J. Hinch said. “And he said he’s about 9.5, so I know he doesn’t take anything for granted.”

Carlton’s MLB debut during Detroit's 7-4 loss to the Reds on Saturday lasted only one pitch, but it was effective. He replaced Joe Jiménez with two outs in the seventh inning following Tyler Naquin’s two-run triple, then used a first-pitch slider to retire Delino DeShields.

Carlton would’ve stayed on to pitch the eighth inning. But when Hinch made the double-switch to bring in Carlton, he mistakenly brought in Akil Baddoo for Derek Hill rather than Eric Haase, who had made the final out of the top of the seventh. Thus, Niko Goodrum batted for Carlton with one out in the top of the eighth.

“Yeah, I screwed that up,” Hinch admitted after the game.

As it was, Carlton’s appearance made history. According to the Elias Sports Bureau, he became the first Tigers pitcher since at least 2000 to throw only one pitch in his MLB debut. He’s the first MLB pitcher to do it since San Diego’s Buddy Baumann on July 16, 2016.

As important as top prospects are to a club’s ability to build a winner, the ability to turn lower-round Draft picks and overlooked prospects into Major Leaguers is arguably just as big. Tarik Skubal’s rise from a ninth-round pick in the 2018 Draft to the front half of the Tigers' rotation was a boon to Detroit. Ryan Kreidler could mean the same if the fourth-rounder from '19 ends up being part of the solution at shortstop.

Carlton goes way beyond that. The Lakeland, Fla., native and former Florida State closer was a 32nd-round pick in the 2017 Draft, the same year the club drafted Alex Faedo in the first round and Will Vest in the 12th. Seventeen of the 31 players the Tigers drafted ahead of Carlton are no longer active in baseball. The lowest-drafted player besides Carlton still active in the system is 18th-rounder Dylan Rosa, currently roaming the outfield at Double-A Erie.

• 2017 Tigers Draft selections

Carlton had a strong college resume. He just doesn’t throw hard, which left him low on Draft boards.

“I’ve always tried to throw hard,” Carlton said. “And when I have tried to throw hard, it usually doesn’t work out for me. The ball usually runs back towards the middle and the ball gets hit. So I just try to stick to my roots of commanding the zone and sticking to the corners of the plate -- just sticking to who I am, really.”

Since joining the Tigers' system, he has shown at every level that who he is as a pitcher, plays.

“He’s got a little bit of a lower [arm] slot and he has really good vertical carry,” right-handed reliever Kyle Funkhouser said. “Not to get too analytical, but his four-seam plays up. And he can put the ball wherever he wants. He’s had success everywhere and he’ll have a lot of success here; it’s just a matter of time.”

When Double-A Erie had its stacked rotation two years ago that included current Tigers starters Skubal, Casey Mize and Matt Manning, Carlton was the closer. The SeaWolves had more intimidating arms in the bullpen, but Carlton outperformed them all.

“It meant a lot to me, having the confidence of the coaches and the manager,” Carlton said, “and it definitely helped my confidence as well for him to put me out there almost every night -- or every other night -- in the ninth inning if we were winning, to go out there and get the job done. I think that really helped me figure out who I was as a pitcher, and the mentality I needed as a pitcher to go out and just get those three outs to get the win.”

Carlton posted 19 saves and a 1.46 ERA over 45 appearances that summer in Erie, allowing just 48 hits over 68 innings with 65 strikeouts. After a lost Minor League season, he tossed 14 1/3 innings of one-run ball last winter in the Dominican Winter League.

Aside from just three saves, his numbers at Triple-A Toledo aren’t far off, with a 3.12 ERA, 43 hits allowed and 48 strikeouts over 49 innings in a more varied role.

Now, with the Tigers needing a fresh arm, he gets a chance to prove himself again, just before his 26th birthday on Wednesday.

“It’s every kid’s dream growing up playing baseball to one day make it to the big leagues,” Carlton said, “and nobody can take that away from me. So I’m very excited to be here and show what I’ve got.”