Heaney (1-2) was charged with the loss against the A's on Friday after surrendering five runs on six hits and a pair of walks while striking out six across 4.2 innings.
Most of Heaney's damage came in the first inning on a home run to Marcus Semien and a two-run double to Stephen Piscotty. From there, the 29-year-old held the A's in check until he unraveled again in the fifth inning, during which he gave up back-to-back doubles to Mark Canha and Matt Olson before he was replaced with Mike Mayers. Heaney has now allowed four or more earned runs in three consecutive starts. He'll look to bounce back Wednesday at Houston.