Why you shouldn't sleep on new Marlins prospect Ethan O'Donnell

On Saturday, the Miami Marlins traded Dane Myers to the Cincinnati Reds in exchange for 23-year-old outfielder Ethan O'Donnell. The timing of the deal was not random—the Marlins had just reached an agreement with free agent Pete Fairbanks and needed to make a corresponding move to open up a 40-man roster spot for him. They got whatever they could for Myers, whose three-year tenure with the Fish had some great stretches, but ended with an ugly half-season slump and yet another injury. This was a sell-low situation.

That being said, O'Donnell is capable of being much more than just organizational filler.

Selected in the sixth round of the 2023 MLB Draft, O'Donnell destroyed Low-A pitching later that summer. In 23 games, he slashed .350/.447/.600/1.047 with a 180 wRC+, including a streak of homering in four consecutive games. That's a rare feat for anybody in the Florida State League.

Moving up to High-A in 2024, O'Donnell slashed .269/.358/.416/.774 with 10 home runs, 40 RBI, 31 stolen bases and a 124 wRC+ in 104 games. He was among Minor League Baseball's hottest hitters in August (1.076 OPS).

The Marlins are getting O'Donnell coming off his worst statistical year as a pro. It included a .236/.327/.325/.652 slash line with seven home runs, 56 RBI, 20 stolen bases and a 90 wRC+ in 125 Double-A games. He struck out 25.6% of the time, but also walked 10.7% of the time.

Just as it was looking like the Reds would be limiting O'Donnell to the outfield corners moving forward, he gave them reason to believe that center field is still a possibility. He played 64 games there, followed by 50 in left field, where he has more than enough arm strength to be successful.

On the surface, O'Donnell's .314 batting average on balls in play may look normal. However, he has a long history of being more productive thanks to his combination of above-average speed, hard contact and skilled bunting. His overall BABIP topped .400 in 2023 when combining college and the minors and he was at .357 in 2024. Perhaps there is some bounce-back potential for him in that category.

It also needs to be noted that the Southern League is an extremely pitcher-friendly league where the average slash line is .230/.321/.340/.660. Since becoming affiliated with Double-A Pensacola, the Marlins have seen a bunch of their prospects take huge steps forward offensively upon being moved up to Triple-A Jacksonville, with Jakob Marsee and Kemp Alderman as recent examples. We'll see if O'Donnell can benefit from the change of scenery like they did. 

One area of focus for O'Donnell should be refining his approach against left-handed pitching. In 2025, he struck out 37.8% of the time vs. lefties with zero homers in 98 plate appearances.

Even if O'Donnell winds up as a platoon player at the major league level, that's an outcome the Marlins would be happy with given the tools he has to impact winning in other aspects of the game.

Interested in learning more about the Miami Marlins' top prospects? Check out our comprehensive top prospects list that includes up-to-date stats, articles and videos about every prospect, scouting reports, and more!