The reliever, who has some experience as a closer, spent most of last season at Triple-A Albuquerque, where he posted a 3.66 ERA over 27 games, while recording 12 saves. He had shoulder surgery in November 2011 and dealt with a groin strain during spring training last year. During a brief nine-game stint with the Dodgers last season he had a 6.75 ERA.
This spring, the 28-year-old had a 2.25 ERA.
In 2011, Guerra took a turn as the Dodgers closer, saving 21 games in his rookie season with a 2.31 ERA. A year later he had a 2.60 ERA for the Dodgers and eight saves. Over his three big league seasons he has a 2.90 ERA.
The native of Denton, Texas was a fourth-round draft pick in 2004. A White Sox bullpen spot became available this past weekend when Mitchell Boggs was released after struggling during Cactus League games.
It isn’t out of the question that the White Sox could use Guerra at closer. That spot opened up when Addison Reed was traded to the Arizona Diamondbacks this winter. Matt Lindstrom and Nate Jones were expected to battle for the closer role this spring, and while the competition continues, they were each slowed by early minor injuries.
Guerra is out of minor league options, so he is expected to make the Opening Day roster. With the move, the White Sox’s 40-man roster is at a full 40 players.