JUPITER, Fla. -- Marlins prospect JJ Bleday isn't the new kid on the block anymore, and he showed it in a powerful way during the ballclub's Grapefruit League opener on Sunday afternoon at The Ballpark of the Palm Beaches.

Serving as the designated hitter and batting ninth in a lineup that also featured prospects Jazz Chisholm and Monte Harrison, the 23-year-old outfielder kicked off his second big league camp with a solo homer in Miami's 6-1 win over Houston. MLB Pipeline's 20th overall prospect stayed with a fastball away from Astros third-ranked prospect Bryan Abreu and sent it over the fence in left-center.

• Chisholm, Bleday among Game 1 standouts

"I think last year, you're nervous, you're excited, you've got all these emotions going on because you know you've never been in a situation like this," Bleday said during a Zoom call on Monday. "I think this year, I'm enjoying it a lot more. I'm a lot more comfortable. I kind of know not to rush myself on my day-to-days and just enjoy. Get what you need in, and then get out."

What struck manager Don Mattingly most about Bleday's performance on Sunday was that he didn't let his first at-bat -- he grounded out after a ball ran in on him -- carry over. In his second chance at the plate, Bleday saw a couple of good sliders. After Abreu tried going in, Bleday displayed an impressive piece of hitting.

It all goes back to Bleday's approach at the plate: Always be on time with the fastball, then adjust to offspeed pitches. Growing up, he enjoyed watching three lefty batters in particular -- Ken Griffey Jr. ("He did everything natural"), Barry Bonds ("Phenomenal mindset at the plate) and Robinson Canó ("Sweet swing").

"I think JJ is one of those guys that just the more you see, the more you appreciate, because you're going to see a good defender, you're going to see a good baserunner, you're going to see a guy that knows who he is," Mattingly said on Monday. "You know how he handles at-bats, how he handles the success in the at-bat or failure in the at-bat. You're getting a polished guy. You just appreciate what he does. I like his whole game. The fact that he is a guy you feel like is not just an all-or-nothing guy obviously helps him."

Per MLB Pipeline's scouting report, Bleday projects as a potential 30-homer threat thanks to his bat speed, strength and the leverage in his 6-foot-3 frame. That wasn't always the case when he emerged as an advanced hitter with a quality left-handed swing and a disciplined approach. His power began to emerge in the Cape Cod League.

Bleday said that his approach of controlling the strike zone and making hard contact to all fields started at an early age. He hates striking out, and he loves letting his pop come naturally.

"Just really emphasizing accuracy over power," Bleday said. "I think when you sacrifice accuracy for power, for me personally, I get in a tough position where you're saying you're just kind of wasting some stuff and things don't go your way. But if you're aggressive and you keep that accuracy first over power, you're eventually just going to keep getting better as a hitter and your walks are going to go up, and your quality of at-bats are just going to turn completely around and just give you that trust and your ability to keep improving, keep growing."

Fellow 2019 MLB Draft pick Kameron Misner, who faced Bleday in Southeastern Conference play when his Missouri Tigers played the Vanderbilt Commodores, was Bleday's teammate in summer ball after their freshman year. He can attest to Bleday's pedigree and growth.

"He's a great player," Misner said. "He knows his swing well, he knows what he does well -- his strengths and weaknesses. He's got a bright future."

After being selected fourth overall in the 2019 MLB Draft, Bleday slashed .257/.311/.379 with a .690 OPS in 38 games at the Class A Advanced level. Before Spring Training shut down last year, Bleday went 3-for-13 with one run, one RBI and six strikeouts across nine Grapefruit League games. When everyone was sent home, he stayed in shape and spent time with family while waiting on a call about a possible Minor League season. Come July, the Marlins had placed him on their 60-man player pool. He and a few others even traveled from the alternate training site in Jupiter to Marlins Park during Summer Camp.

MLB Pipeline projects Bleday, considered a fast riser, to begin his season at Double-A Pensacola. There is a chance he'll receive a Major League callup by season's end. Mattingly, who prefaced his statement by saying he doesn't like putting comparisons on prospects, sees similarities between Bleday and Mets outfielder Michael Conforto. Unlike the development staff, Mattingly has the unique perspective of seeing Bleday's progress from one year to the next rather than on a daily basis.

"With JJ, you feel like you get an experienced mature guy, has good work habits," Mattingly said. "His routines are good. So you just get a solid, solid player with him. And then you just allow him to develop. If he shows up in Miami this year -- you know I can't answer that -- he kind of answers that question with his performance. So, you know, we'll see. But it wouldn't be outside of the realm of possibility, I would say."