The Nationals released Mikolas on Friday, Mark Zuckerman of NatsJournal.com reports.
Mikolas is now officially a free agent after passing through waivers following his removal from the Nationals' 40-man roster. The veteran right-hander has logged a 5.82 ERA and 1.38 WHIP over 116 innings this season and could have to accept a minor-league contract if he wishes to continue his playing career.