Guerra, 28, posted solid numbers this spring -- 2.25 ERA in seven appearances -- but the Dodgers bullpen was simply too crowded for the team to keep him around.
Los Angeles attempted to pass Guerra through waivers, but it's likely that they knew he'd be of interest to several other clubs. Interest in Guerra was reportedly substantial.
Guerra will join Nate Jones, Matt Lindstrom, and Ronald Belisario as aright in the Sox pen. Jones appears to be the favorite for the open closer's job. Lindstrom will likely serve as the eighth-innning/set-up guy, and would presumably be second in line for save opportunities if Jones struggles.
Belisario was listed a potential candidate earlier in the offseason as well, so Guerra might not be in the mix for saves anytime soon, but his late-inning experience could help him make a case to stick in Sox regular sequence.