Mejia (calf) was activated from the 60-day injured list Tuesday, Brandon Warne of ZoneCoverage.com reports.
Mejia hasn't pitched since the end of April due to a calf strain. He posted a very poor 8.74 ERA in 11.1 innings prior to suffering the injury and will have to be significantly better if he's to keep a bullpen job. Ronald Torreyes was outrighted to Triple-A Rochester in a corresponding move.