The Rockies designated Mushinski for assignment Wednesday.
Mushinski opened the season with Triple-A Albuquerque before his contract was selected by the Rockies in early August. He's appeared in eight games for Colorado since his promotion, allowing two runs on nine hits and five walks across 6.2 innings and logging three holds in the process. Mushinski will now go through the waiver process and could carry some appeal to teams with a need for another lefty arm in the bullpen.