After finishing two more games without allowing any additional runs to score, Birtsas made his first start on May 23, against the Baltimore Orioles. He allowed two runs in six innings while striking out five to pick up the win. He was added to the starting rotation shortly afterwards, and had a 9-2 record following a victory over the Mariners in Seattle on August 10. From there, Birtsas went 1-4 with a 6.10 ERA in his next eight starts to finish the season at 10-6 with a 4.01 ERA.