The 26-year-old native of Venezuela made his major-league debut this season with the Orioles. He appeared in six games, all in relief, posting a 6.97 ERA.
The addition makes sense in that Socolovich was signed as an amateur free agent by the Red Sox in 2004, when Cubs president Theo Epstein, general manager Jed Hoyer and senior VP of scouting/player development Jason McLeod all were in Boston.
Socolovich was designated for assignment by the Orioles on Aug. 14. Upon joining the Cubs organization he was optioned to Triple-A Iowa.
To make room on the 40-man roster for Socolovich, Iowa catcher Blake Lalli was designated for assignment by the Cubs.