Barnes threw 2.1 scoreless innings of relief Thursday, allowing two hits and striking out one against the Orioles.
Barnes has pitched seven scoreless frames this spring with eight strikeouts and one walk in five appearances. The conventional wisdom at the start of camp was that Barnes would open the season at Triple-A Pawtucket, but with a need for a temporary rotation fill-in, such as Steven Wright or Roenis Elias, for Eduardo Rodriguez (knee), an opening for a multi-inning reliever on the major league roster may arise.