The left-hander is 50-67 with a 5.05 ERA in 161 games over a six-year career with Detroit and St. Louis. Kansas City invited him to spring training.
The 30-year-old Maroth won a career-high 15 games with Detroit in 2005. He was injured for most of 2006, then was traded from Detroit to St. Louis last June.
Maroth went 0-5 with a 10.66 ERA in 14 games for the Cardinals and missed time with elbow trouble. He finished 5-7 with a 6.89 ERA overall for Detroit and St. Louis in 2007.