The Seattle Mariners are finalizing a deal for star pitcher Luis Castillo of the Cincinnati Reds, sources told ESPN's Jeff Passan Friday night.
Minor leaguers Noelvi Marte, Levi Stoudt, Edwin Arroyo and Dylan Moore are heading to Cincinnati in the deal, sources said.
The Mariners, led by star rookie Julio Rodriguez, entered Friday's action 54-46, 11 games behind the first-place Houston Astros in the AL West and holding onto the second wild-card spot.
Now, they're set to add the best available arm ahead of Tuesday's trade deadline, one who will join an already-solid rotation that includes Robbie Ray and Logan Gilbert.