Eaton will start in right field and bat leadoff Saturday afternoon against the San Francisco Giants. Nationals manager Dave Martinez said last month that Eaton also could play some center field upon his return.
Bryce Harper will start in center field Saturday for Washington.
Eaton had surgery May 10 to repair a chondral flap in his left ankle that was causing pain and has been on the 60-day DL. He has played in just eight games this season, hitting two home runs with five RBIs.