Whalen (shoulder) was placed on the 15-day DL Thursday.
The move was expected after he lasted just 2.2 innings in his last start, as the rookie is dealing with fatigue in his right shoulder. It's unclear if Whalen will be able to return this season, but with little to play for in the standings, Atlanta may elect to play it safely. Brandon Cunniff, Brandon Snyder, and Matt Wisler will all rejoin the major league roster in a series of corresponding moves Thursday.