The Red Sox released Walden on Saturday.
After being outrighted off Boston's 40-man roster in March, Walden pitched exclusively at Triple-A Worcester this season, logging a 4.43 ERA and 1.57 WHIP in 40.2 innings. Set to turn 33 years old in September, Walden isn't any sort of developmental piece for the Red Sox, so the organization elected to move on from him to open up a roster spot at Worcester for a younger player.