The White Sox made move Wednesday.
The 28-year-old Guerra is 4-5 with a 2.90 ERA and 29 saves in three big league seasons with the Dodgers. He missed much of the 2012 season with injuries and had a 6.75 ERA last year in 10 2-3 innings with Los Angeles.
Guerra spent most of last year at Triple-A Albuquerque, going 0-4 with 12 saves and a 3.66 ERA.
''It's potentially another high-leverage arm,'' White Sox general manager Rick Hahn.