The Mariners officially have a full coaching staff for the 2018 season.
If you’re thinking “did the Mariners hire an amalgamation of Yonder Alonso, Adam Lind, and Marc Rzepczynski?” the answer is a hard maybe.
If you’re thinking “Great, but uhh... what’s a bullpen coach actually do?” the answer is uncertain. Ostensibly they are a second pitching coach whose abilities trend towards making pre-game adjustments and being physically ready. DeLunas’ work at CSE Baseball in St. Louis was apparently heavily tied to the types of advanced training methods the Mariners are looking to embrace organizationally.