The Orioles designated Nicolas for assignment Saturday, Jake Rill of MLB.com reports.
Nicolas will lose his place on the 40-man roster in order to make room for Dom Keegan, who was claimed off waivers from Tampa Bay on Saturday. Nicolas has given up seven earned runs in 7.1 major-league innings this season, and he hasn't been much better since joining Triple-A Norfolk (three earned runs in 4.1 IP).