Hearn is scheduled to start Saturday's game against the Mariners.
After working out of the bullpen nearly all season, Hearn was called upon to make his second start of the campaign last weekend in Houston. The lefty faced a strict pitch count, but he dominated during his three innings on the mound, allowing no hits and issuing one walk while striking out three. With Texas dealing away All-Star Kyle Gibson to Philadelphia ahead of Friday's trade deadline, Hearn should fill a permanent spot in the Rangers' rotation.