Mariners left-hander Adam Macko might only be 21 years old, but he’s already traveled the world. Born in Slovakia, he grew up in Ireland, then moved to Alberta, Canada for high school. That’s where the Mariners drafted him, taking him in the seventh round of the 2019 Draft. But when he found out he was coming to Arizona for this year’s Fall League, Macko thought it was the most exciting trip of his life.

“I was ecstatic,” Macko, the Mariners’ No. 8 prospect, said. “I've always wanted to compete at this level. I've had friends that have been at this level as well, and I was always looking up to them. Once I got the call from my coaches, my pitching coach, it was really one of my dreams come true.”

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Slovakia and Ireland aren’t exactly baseball hotbeds and while Alberta isn’t, say, Southern California, it did allow the left-hander to get seen and drafted. He knows how much has been sacrificed to get him to this point and what it would mean for him to reach Seattle and become the third Slovakia-born player in the history of the big leagues.

“It's everything, really,” Macko said. “It just reflects how many people I've been surrounded with that helped me to get here. My parents got to be number one that have gone through a lot, moving countries, traveling, just so that we can have a better future. It would make everything really worth it.”

To get there, Macko is going to have to stay healthy. While he’s gotten much bigger and more physical since he was drafted, he’s logged just 95 career innings since he made his pro debut in 2019. Rotator tendinitis in 2021 limited him to 33 1/3 innings. This past season, an elbow strain and then meniscus injury shelved him for all but eight starts spanning 38 1/3 IP. So this fall, aside from the challenge of facing a much higher level of hitter than he’s ever seen, is to get reps and continue a progression he had embarked on at the Mariners’ facility in Peoria.

“I'm building up right now, from a couple of things that I was rehabbing down here in Arizona, so I'm looking to stay healthy, keep feeling good,” Macko said. “I think I've figured my body out pretty well, so I guess just put out a good show and stay healthy.”

He has the stuff to join the pitchers he grew up idolizing and learning from. Macko was somewhat self-taught early in his life, watching YouTube videos of pitchers to provide a foundation the Mariners hope they can help develop into a big league starter.

“Justin Verlander was one of the first, as soon as I saw a game on TV. I looked up the best pitcher and it was Justin Verlander at the time,” Macko said. “So it was him at first, I tried to make myself exactly like him. And then David Price later on. And now it's kind of kind of all over the place. I'm learning to appreciate the small things out of all the pitchers.”

Mariners hitters in the AFL

Alberto Rodriguez, OF (No. 14): Acquired from the Blue Jays in the 2020 Taijuan Walker deal, Rodriguez had a very solid first full season with the Mariners in Single-A ball in 2021 but wasn’t as impactful this past year with the move to High-A, where he ended the previous season. He just turned 22, and the Mariners are hoping their outfielder can continue to learn to do more damage and improve his batted ball profile.

Robert Perez Jr., 1B (No. 21): Perez mashed across two levels of A ball in 2022, finishing with a .921 OPS, 27 homers and 114 RBIs. For him to have that kind of success as he moves up the ladder, he’ll have to make better swing decisions and not be as aggressive in terms of expanding his zone.

Jose Caballero, INF: This is Caballero’s third trip to the AFL, having played in 2019 and 2021. He missed nearly all of the 2022 season, first with a broken left hamate and then a fractured right hand. He’s always had very impressive contact skills and the Mariners want him to continue that while trying improve his ability to impact the ball to his pull side.

Spencer Packard, OF: Packard, originally a product of Canyon del Oro High School and eventually drafted in the ninth round of the 2021 Draft out of Campbell, returns home to Arizona. He also missed time with a hamstring injury. Packard, who turns 25 at the end of October, can use the Fall League to help prepare for the upper levels of the Minors, while also working to be on time more consistently against velocity and not chasing breaking stuff out of the zone.

Mariners pitchers in the AFL

Bryan Woo, RHP (No. 15): The Cal Poly product got hurt in his Draft year and needed Tommy John surgery, but the Mariners liked his stuff enough to take him in the sixth round of the 2021 Draft. He came back this year and threw well with a solid three-pitch mix. He’s continuing to get stretched out and get more innings while learning to attack the zone more early in counts.

Ty Adcock, RHP: Adcock was drafted out of Elon in 2019, but didn’t make his pro debut until this season, throwing eight total innings. He mostly needs innings after so much time off the mound.

Jorge Benitez, LHP: Benitez tied for the system lead with 14 saves across both levels of A ball in 2022, showing an ability to miss bats (11.5 K/9) and get hitters out (.205 BAA). He’s working on refining the command of all his stuff, especially his lively four-seamer.

Juan Then, RHP: This is Then’s second stint with the Mariners, having initially signed with Seattle, then was traded to the Yankees before being re-acquired a couple of years later. He’s always had good stuff and he’s back in the AFL for the second straight year to make up for lost innings (elbow sprain) while working on winning early counts and not trying to be too fine and trusting his stuff.