Tarnok will serve as the primary pitcher for the Athletics on Wednesday against the Rangers, Martin Gallegos of MLB.com reports.
The Athletics will likely deploy an opener in front of him, but Tarnok is slated to work multiple innings Wednesday and profiles as the Oakland pitcher most likely to factor into any decision. The 24-year-old right-hander has posted a 6.75 ERA and 10:9 K:BB through 10.2 major-league frames this season. He looks like he could get a spin in the No. 5 spot in the rotation after Oakland recently demoted Hogan Harris to Triple-A Las Vegas.