Seattle put Fister on the 15-day disabled list Sunday and called up left-hander Luke French from Triple-A Tacoma, a move that brings immediate relief to a shorthanded bullpen.
"I don't know if his medical condition has changed any more, it's still a fatigued arm, but this is two-fold," Wakamatsu said. "Luke French gives us needed help in the bullpen right now. Our bullpen is pretty fatigued right now with [Sean White] being out today, and [Chad Cordero] and [Garrett Olson] have both thrown two days in a row."
Fister's placement on the DL is retroactive to June 1, and Wakamatsu is aiming for him to return to the rotation on June 16 for the finale of a three-game series against the Cardinals in St. Louis. In the meantime, Ryan Rowland-Smith will continue to hold Fister's spot.
Working as a reliever will be a role change for French, who made all 11 of his appearances for the Rainiers as a starter. He posted a 6-2 record and 1.93 ERA with one complete game, and because he was scheduled to start Sunday in Tacoma, he's ready to go.
"The fact of the matter is, I need to be ready to pitch whenever they ask me to pitch, and that's the way I'm going to approach it," French said.
Meanwhile, shortstop Jack Wilson was scheduled to make a rehab start with Triple-A Tacoma on Sunday, but he was scratched from the lineup because of a wet field. Wilson has been on the disabled list since May 6 with a right hamstring strain.