Olmos, 25, posted a 2.13 ERA in his first five appearances with the Mariners, earning his first win in relief against the A's on Aug. 25. The left-hander then struggled in his second start on Friday in Oakland, allowing five runs on six hits in 1 1/3 innings. He joins a Rainiers team that will wrap up its season on Monday in Las Vegas.
"[Farquhar] gives us the best chance to win a ballgame today," said Mariners manager Lloyd McClendon. "It's the only game we got today. That's the only one I'm worried about."
With Olmos no longer in the Mariners' rotation and left-hander James Paxton still not available after tearing the finger nail on his left middle finger in a rehab start in Salt Lake City on Wednesday, McClendon still has a Wednesday starting pitcher slot to fill between Tuesday starter Taijuan Walker and Thursday starter Felix Hernandez.
Swing man Vidal Nuno is likely to get the spot start barring an extended relief outing in the next two days, but McClendon wouldn't commit to the left-hander when asked about his plans on Monday.
"I don't know what that means on Wednesday. I have no idea," McClendon said. "I'm playing Texas, I don't know who my personnel is. We'll figure that out on Wednesday. I've got guys banged up all over the place."
McClendon also declined to announce likely call-ups when Tacoma's season ends Monday night. Nuno, 28, has started five games for the Mariners this season and is 0-2 with a 3.72 ERA in 26 games with Seattle. He is winless in his last 20 starts dating back to last June.
Andrew Erickson is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.