He made one spot start for Seattle on April 17 this season, giving up six hits and one run over five innings in a no-decision against Houston and was 5-0 with a 3.97 ERA in 10 games (nine starts) for Tacoma.
Miranda filled a big role last year for an injury-plagued Mariners rotation, but Seattle's top starters have stayed healthy so far this season as the club has gotten off to a 55-32 record.
James Paxton, Felix Hernandez, Mike Leake and Marco Gonzales haven't missed a turn yet and Wade LeBlanc has filled in for an injured Erasmo Ramirez the last 12 starts and just signed a contract extension through 2019.
Ramirez is getting close to beginning a Minor League rehab stint as he returns from a shoulder issue and the club has lefty starter Roenis Elias in long relief on the big-league club.
Rob Whalen, Christian Bergman and Casey Lawrence have also been pitching well in Tacoma this season, along with the potential of picking up another starter as the July 31 non-waiver Trade Deadline approaches.
Miranda was acquired from the Orioles on July 31, 2016 in exchange for lefty Wade Miley and has compiled a 13-9 record and 4.72 ERA in 44 games (40 starts) over three seasons in the Majors.