The Orioles designated Roa for assignment Friday, Roch Kubatko of MASNSports.com reports.
Baltimore claimed Roa off waivers from the Twins last weekend, but he loses his 40-man roster spot to trade pickup Eduarniel Nunez, who was acquired from the Athletics on Friday. Roa has a career 3.86 ERA and 9:10 K:BB across 11.2 big-league innings.