Cooper is out of the lineup for Wednesday's game against Atlanta, Mac Cerullo of the Boston Herald reports.
Cooper served as Boston's designated hitter in both of the past two games and went 0-for-8 with four strikeouts. He'll cede DH duties to Rob Refsnyder on Wednesday, and with Tyler O'Neill (knee) returning from the 10-day injured list one day after Wilyer Abreu (ankle) was deactivated, Boston will likely have room in the lineup against right-handed pitching for only one of Refsnyder and Cooper moving forward. Refsnyder has performed far better than Cooper so far this season, so it wouldn't be surprising if Boston opted to make the former a greater priority in the lineup.