Sullivan, 32, played parts of six seasons with the Rockies, Mets and Astros. He hit .294 in his rookie season of 2005 but went backward from there and was released out of the Phillies' Triple-A club last May.
Ledezma, 30, is the most accomplished of the pitching group and would seem to have a chance of making the 40-man roster as a situational lefty, especially if Hong-Chih Kuo does not return. Ledezma also spent most of 2011 in the Minor Leagues, with 11 games for Toronto.
Castillo is a 35-year-old left-hander from Cuba who had a 2.31 ERA in 17 games in 2011 for the D-backs. He missed August with shoulder tendinitis.
Bard, 33, has played with five teams and hit .210 in 26 games for Seattle in 2011, when he spent most of the season at Triple-A.
The others are right-handed pitchers Angel Guzman, Fernando Nieve, Jose Ascanio, Ryan Tucker and Will Savage; left-handed pitchers Matt Chico and Scott Rice; infielders Jeff Baisley, Lance Zawadzki and Luis Cruz.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.