Clemens, acquired two years ago from the Braves as part of the deal that sent Michael Bourn to Atlanta, is taking the rotation spot formerly occupied by the veteran Erik Bedard, who has been moved to the bullpen for the rest of the season.
The addition of Clemens means that all six of the Astros' starters are 25 or younger. Clemens joins Brad Peacock (25), Dallas Keuchel (25), Brett Oberholtzer (24), Jarred Cosart (23) and Jordan Lyles (22), who's the youngest and most experienced of the bunch.
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.