Heaney is scheduled to start Saturday's game against the Mariners in Seattle, Evan Grant of The Dallas Morning News reports.
The veteran southpaw has made his last six appearances in relief, with the most recent outing coming in the series opener Thursday, when he tossed a 17-pitch scoreless inning. Given that he hasn't covered more than five innings in a game since late August, Heaney could end up serving as more of an opener or piggyback starter rather than a traditional starter Saturday. The Rangers will have Martin Perez (five days' rest) and Cody Bradford (three days' rest) available as potential bulk-relief options to work behind Heaney.