Mariners promote highly regarded reliever Edwin Diaz

ARLINGTON, Texas – The tantalizing power that right-hander Edwin Diaz potentially lends to the Seattle Mariners’ bullpen finally proved too much to resist.

The Mariners promoted Diaz, 22, directly from Double-A Jackson prior to Saturday’s game against the Texas Rangers after clearing space by optioning right-hander Cody Martin back to Triple-A Tacoma.

Manager Scott Servais indicated Diaz, who will wear No. 39, will likely be used initially in low-leverage situations as an acclimation to the big leagues.

“Probably much like we did with Mike Montgomery making the transition from starter to reliever,” Servais said. “We’re not going to overdo it. But he’s started. He can go length. Obviously, with the stuff he’s got, he can go shorter bursts for us.

“We’ll ease him in.”

Diaz is generally regarded as the organization’s most advanced pitching prospect, which prompted the Mariners to shift him to the bullpen on May 10 in hopes of accelerating his development.

“They told me (by changing to a reliever) I can be in the big leagues quick,” Diaz said. “The first time I came out the bullpen, I was little excited, but I got the three outs. Then I started to think more like a reliever.”

Results exceeded all expectations.

Diaz allowed one unearned run and just three hits in 11 2/3 innings at Jackson over 10 appearances. He also struck out 16 and walked just two.

“I go more with a fastball and slider,” Diaz said. “As a starter, I need to throw more change-ups. As a reliever, I want to attack the hitter. I want to command my fastball, and then let’s see what happens.”

Reports say his fastball ticked up from the low 90-mph range as a starter to the mid-to-upper 90s, but his slider remains a work in progress. One scout said, “Too often, it still just spins up there.”