Astros catcher Jason Castro who has a long history of knee problems that once threatened his career has been shut down for the remainder of the season. Brian McTaggart of reports that the injury is officially being called right knee discomfort but Castro has been placed on the disabled list and will miss the final two weeks. Castro had a cyst removed from the same knee on September 3 and has been limited to just two games since then both of them as a designated hitter.