The Nationals on Monday put ace right-hander Max Scherzer on the injured list with a mild rhomboid strain, retroactive to July 26.
Washington recalled right-hander Erick Fedde from Double-A Harrisburg and he is likely to start Tuesday against the first-place Atlanta Braves, who begin a three-game series at Nationals Park on Monday.
Scherzer is 9-5 with 2.41 ERA in 20 starts this year and leads the league with 189 strikeouts. He has made just one start since his outing at home July 6 against the Kansas City Royals. He went five innings on Thursday at home against Colorado and complained of back problems after he allowed three runs.