The Guardians recalled Castro from Triple-A Columbus on Tuesday, Mandy Bell of MLB.com reports.
Castro is eligible to rejoin the 26-man active roster less than a week after being optioned to Columbus since the Guardians placed catcher Austin Hedges (concussion) on the 7-day injured list in a corresponding move. Over eight innings out of the Cleveland bullpen this season, Castro has given up eight earned runs on 11 hits and seven walks while striking out 10.