Miami Marlins pitcher Matt Moore
Matt Moore was designated for assignment by Miami as he was not eligible for the postseason roster because he was claimed off waivers in mid-September, but he has had a great season.
A former top pitching prospect with the Rays, Moore has found a home in the bullpen at the back end of his career and he has seen success. In 46 combined appearances this season with the Angels, Guardians, and Marlins, he has a 2.77 ERA and a 10.5 K/9.
Similar to Chafin, Moore can be a high-leverage reliever to get right-handed and left-handed hitters out, Chafin has more experience but Moore has had a better season. If the Cardinals wanted to pursue a left-handed bullpen piece they have a couple of good options.