On May 5, 2019, Sittinger was promoted to the Erie SeaWolves of Double-A but would be demoted to the Flying Tigers again 7 days later. On June 2, he was once again promoted to the SeaWolves but would be put on the 7-day injured list 6 days later. On June 27, he would be again demoted to the Flying Tigers 4 days after being taken off the injured list. On July 12, Sittinger was released by the Tigers. Overall in 2019 across all levels, he went 0-2, pitched 28 innings in 20 games, had a 7.39 ERA, a 1.86 WHIP, and struck out 29.
