The Mariners have promoted pitching prospect Taijuan Walker to Triple-A Tacoma.
Walker was 4-7 with a 2.46 ERA and 96 strikeouts for Double-A Jackson to earn the promotion. He will make his Tacoma debut on Tuesday against the Fresno Grizzlies.
"We feel that Taijuan has accomplished his goals at Double-A and it's time for the next step in his career," Mariners general manager Jack Zduriencik said.
Walker leads the Southern League in strikeouts and is seventh in ERA. He was the 43rd overall pick in the 2010 draft by the Mariners.
Lefty Danny Hultzen, who has a left rotator cuff strain, will throw five innings tomorrow in Arizona. If it goes well, he will pitch Thursday for the Rainiers.