Zimmermann, 32, had another subpar season, going 7-8 with a 4.52 ERA and a 111/26 K/BB ratio in 131 1/3 innings across 25 starts for the Tigers. In three years since signing with the Tigers as a free agent, he has a 5.24 ERA across 72 starts and one relief appearance. Zimmermann has two years and $50 million remaining on his contract.
Stewart, 24, was a September call-up, playing some outfield. He hit a solid .267/.375/.417 with a pair of homers and 10 RBI in 72 plate appearances.