Rea was assigned to the Cubs' alternate training site in South Bend Thursday, Jordan Bastian of MLB.com reports.
EDGE Analysis
Rea was in the mix to begin the year as the team's fifth starter with Jose Quintana (thumb) out, but with Alec Mills securing that role, Rea was kept off the Opening Day roster. The 30-year-old last appeared in the majors in 2016, when he logged 20 total games (19 starts) with the Marlins and Padres.