Calero, 34, is an intriguing acquisition, having amassed significant playing time with St. Louis and Oakland from 2003-07. The St. Thomas University product has made 246 major league appearances over his career. He appeared in just five games last season for Oakland before the A's released him in June.
Standridge is a former first-round pick by Tampa Bay and has 60 career big-league appearances on his resume. He spent last season in Japan.