Fallen Mariners prospect is slowly but surely starting to redeem himself

Once hailed as one of the crown jewels of the 2023 international signing class, Felnin Celesten’s journey through professional baseball has already been filled with high expectations, early stumbles, and now signs of a promising turnaround.

The 19-year-old shortstop, signed by the Seattle Mariners for $4.7 million in 2023, entered the system with superstar projections — tools, swagger, and athleticism that made scouts dream. But like many teenage prospects making the leap to full-season ball, the transition hasn’t been seamless.

After a slow start to his 2025 season in Modesto, Celesten’s stock fell quickly. Through his first 39 games, he slashed to a modest .672 OPS with just 2 home runs, 24 RBIs, and 39 strikeouts in 183 plate appearances. At times, his swing seemed rushed, and his in-game instincts hadn’t quite caught up to his raw tools. 

Once-hyped Mariners prospect is quietly starting to turn a corner

Then came an unexpected pause with Celesten disappearing from the lineup. In early June, the switch-hitting shortstop was sidelined for two weeks after experiencing an unexplained dizzy spell that resembled vertigo. Mariners general manager Justin Hollander spoke candidly about it in an interview:

“He had some dizziness, so they had him see the doctor — vertigo-like symptoms,” Hollander said. “He’s feeling better now. The dizziness, we don’t really have a way of tracking what it came from… But he’s back DH-ing now. It was a little weird that when he ramped up activity, things started to move.”

It’s unclear whether this bout of dizziness had lingered prior to his time off, possibly affecting his performance. But what is clear is that since returning to the lineup, Celesten has looked far more like the player the Mariners believed they were signing.

Over his last 26 games, Celesten has posted a robust .866 OPS, with 2 home runs, 13 RBIs, 14 walks, and 29 strikeouts in 116 plate appearances. And in July alone, he’s sporting a scorching .981 OPS — offering his most productive stretch since turning pro. He’s showing more plate discipline, better contact quality, and signs that the game is slowing down for him.

Once considered a top-of-the-scale runner, there’s been some recalibration to those projections. A hamstring issue and the overall wear of full-season ball have made it more likely that he settles in as an above-average runner instead of an elite one. But that doesn’t mean his future impact is diminished. If anything, it reinforces the importance of health and reps — something that has eluded Celesten in his brief career so far.

The biggest question now isn’t about tools. It’s about durability. Celesten still has the traits that made him a headline prospect. But if he’s going to recapture his place on national top-100 lists, it’ll come down to logging a full, healthy season. The talent hasn’t gone anywhere — but the consistency, availability, and maturity to convert it into results will be what defines his next chapter.