The Seattle Mariners starting rotation was the team's most sure thing when spring training began. The group featured three All-Stars and two more pitchers heading into their third respective seasons in the majors.

After the Mariners announced Logan Gilbert as the opening day starter, Luis Castillo was super happy for his teammate.

Making his fourth start of the spring, Luis Castillo worked into the fifth inning before reaching his pitch limit of 65. After holding the Padres scoreless over the first three innings, he allowed two runs in the fourth on a solo homer from Gavin Sheets and an RBI double from Connor Joe.