When the Marlins scouted prep catcher Joe Mack, they saw him compete in three sports: basketball, volleyball and baseball. In one particular instance, director of amateur scouting DJ Svihlik returned to upstate New York and caught him taking batting practice the morning after a district championship volleyball match. 

"It's very impressive when young players will do that, and you can't understate how important it is that they are playing multiple sports," Svihlik said. "That plays into the fact that he hasn't played as much as some other guys, and then to go out last summer and to perform like he did on the biggest stage and be as competitive and successful, that gives you a lot of comfort that you got a player that just [not only has] tools, but he can actually play the game. So I was really excited."

The Marlins selected Mack in Competitive Balance Round A (No. 31) in the 2021 MLB Draft on Sunday after picking high school shortstop Kahlil Watson 16th overall. The approximate pick value for Mack's slot was $2.31 million. Miami has a bonus pool of $9,949,800.

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Mack, who attended Williamsville East High School in New York, ranked as MLB Pipeline's No. 19 overall Draft prospect. According to his scouting report, he stood out at events like the East Coast Pro Showcase and Area Code Games both at the plate and behind it. A left-handed hitter, Mack showed off an advanced approach that set him apart as one of the premier players in the country last summer, with alley-to-alley gap power. He has the strength and bat speed to display at least average pop.

Svihlik called him a bat-first catcher, who has "some ups. And he's powerful and he's explosive and he's everything you're looking for in a good dependable, reliable catcher."

Behind the dish, Mack had plus pop times to second base, consistently under 1.9 seconds. He'll need to keep working on his overall defensive game, but given his baseball awareness, Mack will be at least a solid receiver. The 18-year-old is a Clemson commit.

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The 6-foot-1, 210-pound Mack got a late start to his senior season because his volleyball team reached the state final. He made it worth the wait, posting a .500 average with eight homers, 22 RBIs and 26 stolen bases in 21 games. His performance garnered him All-Western New York Player of the Year honors for the second time.

"I don't know what to say," Mack told MLB Network after being picked. "I'm just really excited, really blessed and really thankful for this opportunity. Go Marlins! Let's go."

Mack, whose older brother, Charles, was taken in the sixth round of the 2018 MLB Draft by the Twins, is the highest catcher selected by the Marlins since Kyle Skipworth (sixth overall) in '08. Like most organizations, that is a position of need for the Marlins. Will Banfield (No. 26) is the only backstop among Miami's top 30 prospects.

"I think there's absolutely no question that Joe Mack will be a catcher for the entirety of his professional career, unless there's some injury or [something] like that," MLB Pipeline's Jonathan Mayo said. "For me, he was maybe the best all-around catching prospect in this class just in terms of the certainty that he stays behind the plate. He receives well, he throws well, the bat is very good. It was heating up as the spring wore on, [he] made [adjustments] at the plate. He was starting to hit a little bit more like he had over the summer against premium competition, which can be a little bit of a concern when you're talking about a guy from upstate New York -- he's not facing great competition. This is a really good pick. The Marlins -- talk about going up the middle -- Kahlil Watson and Joe Mack in one Draft, that's how you build an organization."

Day 2 of the 2021 Draft, which will span rounds 2-10, begins at 1 p.m. ET on Monday. The Draft will conclude with rounds 11-20 on Tuesday, starting at noon. MLB.com will simulcast MLB Network’s broadcast and provide live coverage.

To view when teams pick, the Top 200 Prospects list, scouting video and more, visit MLB.com/Draft. Follow @MLBDraft and @MLBDraftTracker on Twitter to see what Draft hopefuls, clubs and experts are saying and to get each pick as it’s made.