Outfielder Michael Morse is expected to be a designated hitter when the Nationals play the Red Sox at Fenway Park starting Friday. It will give Johnson an opportunity to play either Roger Bernadina or Rick Ankiel in the outfield. Both players have been benched because of the emergence of Bryce Harper and Steve Lombardozzi.
Mark DeRosa is expected to start a rehab assignment either Thursday or Friday. He will most likely play for Class A Potomac. DeRosa has been on the disabled list because of a left oblique strain.