The Seattle Mariners are calling up right-hander George Kirby, one of the best pitching prospects in baseball, sources told ESPN's Jeff Passan on Saturday.
Kirby, who was scratched from his start for Double-A Arkansas on Saturday, will be making his major league debut for the Mariners against the Tampa Bay Rays on Sunday, sources told ESPN.
The Mariners on Thursday had optioned young right-handed starter Matt Brash to Triple-A Tacoma, with the plan to transition him to a bullpen role for the rest of the season.
Kirby, a 24-year-old who was the 20th overall pick in the 2018 MLB draft out of Elon, has a huge ceiling with excellent command and above-average stuff, including his fastball, which averaged 97.