Nuno was optioned to Triple-A Norfolk on Saturday, Rich Dubroff of PressBoxonline reports.
Prior to Friday's rough outing, the southpaw had lowered his ERA to 3.12. However, Nuno allowed his third home run of the season in his brief appearance versus the Yankees, leading the Orioles to send him down for more work. Baltimore is fairly thin on lefties with the departures of him and Jayson Aquino, so Nuno could return to the big leagues fairly soon if the Orioles need a lefty in their relief corps again.