The Astros announced Friday that they have placed RP Chad Qualls on the 15-day DL with an as-yet undisclosed injury, and recalled 1B Jon Singleton.
#Astros place RHP Chad Qualls on 15-day DL, recall first baseman Jon Singleton from AAA Fresno.
— #VoteAltuve (@astros) June 26, 2015
Though no injury has been announced/leaked, that there is an injury makes sense. Qualls has struggled through June with an 8.44 ERA while walking 4 batters and allowing 2 HR in 5 innings during that time. While such abysmality can be explained away by statistical small sample, it can also be explained by a nagging injury that the pitcher has been quietly dealing with.