The Red Sox signed Guerrero to a minor-league contract Saturday, Andrew Parker of SoxProspects.com reports.
Guerrero played in Japan's Nippon Professional Baseball league with the Chiba Lotte Marines last year, posting a 6.41 ERA with a 15:8 K:BB over 19.2 innings spanning 21 games. The righty reliever has 113 games of MLB experience, logging a 5.77 ERA, 1.66 WHIP and 111:67 K:BB across 106 frames between the Padres and Marlins. Considering that Guerrero last pitched in the majors in 2019, he's a long shot to make an impact with the Red Sox during the upcoming campaign.