Source: Nats to promote pitching prospect Cornelio on Friday

Riley Cornelio, who has become one of the Nationals' most-intriguing pitching prospects, will be called up from Triple-A before Friday's game

The Nationals are calling up right-hander Riley Cornelio, who over the last year has climbed the organizational ladder to become one of the club’s most-promising pitching prospects, and expect him to be available out of the bullpen Friday night in Chicago, a source familiar with the decision confirmed.

The club isn’t planning for now to start Cornelio in the series opener against the White Sox, though he’ll be on a full four days’ rest since his last start at Triple-A Rochester and could be available for a long-relief role behind scheduled starter Miles Mikolas. The Nats have used left-hander PJ Poulin as an opener for Mikolas each of his last two turns in the rotation, with Mikolas enjoying his best performance of the young season with four scoreless innings Sunday against the Giants.

Cornelio, whose promotion was first reported by The Athletic, has loomed as an intriguing potential call-up since impressing team officials during spring training, his first in big-league camp. A seventh-round pick in 2022 out of TCU, he put up nondescript numbers at low Single-A Fredericksburg in 2023 and high Single-A Wilmington in 2024 before breaking through last season.

In 27 total games split between Wilmington, Harrisburg and Rochester in 2025, Cornelio delivered a 3.28 ERA and 1.146 WHIP. That earned him organizational Pitcher of the Year honors and a spot on the 40-man roster, which includes an automatic invitation to big-league spring training.

With a new front office and coaching staff in place this spring, Cornelio impressed in two Grapefruit League relief appearances, allowing one run over five innings while striking out seven with zero walks and flashing a 97-mph fastball.

Though the notion of keeping Cornelio in their major-league bullpen was intriguing, the Nationals wanted to keep him on a starter’s schedule in Rochester. He came out of the gates strong, going 2-0 with a 2.45 ERA in four starts, striking out 27 while walking only eight in 18 1/3 innings. He last pitched Sunday against Buffalo, allowing one run over five innings with nine strikeouts.

Whenever Cornelio makes his major-league debut, he’ll become the 22nd different pitcher used by the Nationals (who today played their 26th game) this season. He replaces reliever Julian Fernandez, who was optioned to Triple-A following today’s 7-2 loss to the Braves.