This red-hot KC Royals prospect is rewriting his career narrative in 2025

The Kansas City Royals need every prospect development win they can get as they continue to rebuild one of baseball’s weakest farm systems.

With top prospect Jac Caglianone finding his footing at the major-league level, a new name will soon take over the mantle as Kansas City’s No. 1 prospect. Catcher Blake Mitchell and pitcher David Shields are the obvious candidates based on pedigree, but if game-level results drove the conversation, resurgent right-hander Yunior Marte would deserve serious consideration.

KC Royals fans shouldn't overlook Yunior Marte turning things around

The Royals have taken a more aggressive approach to the international signing period in recent years, and signing Dominican Republic native Marte in 2022 was one such move.

Marte opened the 2025 season with the Low-A Columbia Fireflies after a challenging 2024 campaign at the same level. Injuries sidelined him for most of last season, and in his two brief appearances, he posted a 6.48 ERA and a 1.80 WHIP. While he remained on the fringes of Kansas City’s top 30 prospect rankings, some of his early shine had clearly worn off.

At just 21 years old, 2025 has shaped up to be a pivotal year for Marte—and he’s more than delivered. Through 12 starts with the Low-A Columbia Fireflies, Marte boasts a 2.70 ERA and a 1.02 WHIP, ranking among the best marks of any starter in the Royals’ farm system.

He’s also been remarkably consistent, allowing no more than four hits or two earned runs in each of his past seven starts. His most dominant outing came on May 9, when he struck out nine, walked just one, and allowed three hits over five scoreless innings. That May run earned Marte Carolina League Pitcher of the Month honors—becoming the first Fireflies hurler to win the award since Steven Zobac in April 2023.

Marte remains a volatile prospect in the eyes of evaluators. He doesn’t appear on MLB Pipeline’s Top 30 list for the Royals’ system, yet Baseball America ranks him 15th. Writer Bill Mitchell recently spoke with Royals director of pitching performance Paul Gibson, who praised Marte’s development, noting his “progress has been really good” and specifically highlighted improvements in “staying down the line longer.”

Marte leans on a fastball/slider combo, with both offerings graded as above average by Baseball America. He’s still refining a split-changeup to complement a two-seam fastball that sits comfortably in the mid-90s. That third pitch could ultimately determine his long-term role—whether he profiles as a reliable bullpen arm or a viable back-end starter.

For now, Marte remains on the starter development track, and his bounce-back from a disappointing 2024 campaign has been nothing short of impressive.