The Cardinals made the move Wednesday. Aardsma began this spring with Cleveland.
The 32-year-old Aardsma likely leaps to the front of a list of candidates that includes Kevin Butler, Scott McGregor and Jorge Rondon.
Aardsma is 23-15 with 69 saves and a 4.23 ERA in a seven-year major league career. The righty was 2-2 with a 4.31 ERA in 43 games for the Mets last year after missing almost two seasons with injuries.
Aardsma joins shortstop Jhonny Peralta in the Cardinals’ clubhouse. After Peralta finished a 50-game drug suspension last year with Detroit and later signed a $53 million, four-year deal as a free agent with St. Louis, Aardsma tweeted: “Apparently getting suspended for PED’s means you get a raise. What’s stopping anyone from doing it?”