Yarbrough was optioned to Triple-A Durham on Tuesday, Juan Toribio of MLB.com reports.
Yarbrough's 4.55 season ERA is nothing special, but he's allowed just two runs in 15 innings over his last four appearances, so the timing of the move is odd. He's expected to make a start at Durham before returning to the Rays following the All-Star break, Marc Topkin of the Tampa Bay Times reports. Austin Pruitt was recalled in a corresponding move.