Well, this came out of the proverbial left field. From the press release:
The Chicago Cubs today selected the contract of right-handed pitcher Esmailin Caridad from Triple-A Iowa. To make room for Caridad on the roster, the Cubs optioned right-handed pitcher Jeff Stevens to Triple-A.
Caridad, who will wear uniform number 33, joins the first major league roster of his career and is available for tonight’s game in Colorado.
The 25-year-old Caridad is 5-10 with a 4.15 ERA (58 ER/125.2 IP) in 23 starts with Iowa this season, including a 1-1 record with a 2.74 ERA (7 ER/23.0 IP) in his last four starts. He was a non-roster invitee to Cubs spring training in 2009, posting no record and a 0.00 ERA (6.0 IP) in six Cactus League relief appearances.