Heaney will make his first start since April 5, 2016, after undergoing Tommy John surgery in July 2016. The left-hander has had a smooth recovery and was 6-4 with a 3.49 ERA in 2015.
Hellickson, who the O's acquired at the Trade Deadline from the Phillies, is 1-2 with a 4.50 ERA in three starts for Baltimore. He allowed five runs on six hits over five innings in the Orioles' 9-3 loss to the A's on Sunday.