The Athletics designated Martinez for assignment on Sunday.

Martinez didn't factor into the decision in the Athletics' loss to the Mariners on Monday, allowing an earned run on five hits and a walk over four innings. He also recorded a strikeout and uncorked two wild pitches.

Martinez (0-2) took the loss against the Royals on Wednesday, allowing an earned run on three hits, a hit batsman and a walk over 2.1 innings. He struck out three.

Martinez is listed as the Athletics' starting pitcher for Wednesday's game against the Royals, Martin Gallegos of MLB.com reports.

Martinez, recalled from Triple-A Las Vegas earlier in the day, allowed two earned runs on four hits and three walks over 4.2 innings during a loss to the Rangers on Tuesday. He recorded five strikeouts and did not factor into the decision.

Oakland recalled Martinez from Triple-A Las Vegas on Tuesday.

Martinez was optioned to Triple-A Las Vegas on Saturday, Matt Kawahara of the San Francisco Chronicle reports.

Martinez, activated from the injured list earlier in the day, fired two scoreless innings in which he allowed a hit and recorded two strikeouts during a loss to the Diamondbacks on Monday.

The Athletics reinstated Martinez (elbow) off the 15-day injured list Monday.

Martinez (elbow) made a rehab appearance for Triple-A Las Vegas on Tuesday, covering 1.2 innings while allowing one earned run on three hits and two walks.