The 30-year-old out of Colombia last pitched in the Majors in 2019 with the Marlins. Prior to his run with the Marlins, he had debuted with the Padres, making just one two-inning outing in 2016. Signed as an amateur free agent back in 2009, Guerrero came up in the Padres system before being included in the 2016 deadline deal that brought Carter Capps, Luis Castillo, Jarred Cosart, and Josh Naylor to the Padres from the Marlins for Andrew Cashner, Colin Rea, and Guerrero. It wouldn’t be until 2018 that Guerrero would get significant run out of a big league bullpen.
Between 2018 and 2019, Guerrero would make 112 appearances for the Marlins totaling 104 innings. Cumulatively, he put up a 5.80 ERA/5.09 FIP, 22.9 percent strikeout rate, 13.6 percent walk rate, and 44.4 percent groundball rate. After the 2019 season Guerrero was claimed off waivers by the White Sox.
Guerrero spent last season in the White Sox system at Triple-A Charlotte. There, he appeared 18 times with a 6.63 ERA over 19 innings. In the NPB, Guerrero will have the chance to pitch professionally and establish value as a bullpen piece. Once upon a time, he had been a top-30 prospect in the Padres system, but control problems have largely kept him from establishing himself at the sport’s highest level.