Astros signed LHP Zach Duke to a minor league contract. The deal also includes an invite to spring training. Duke spent time on the disabled list and didn't perform for Arizona this past season, posting a 4.93 ERA and 32/19 K/BB ratio over 76 2/3 innings. He'll compete for a rotation spot in spring training but will probably only have a real shot if Wandy Rodriguez and/or Brett Myers are traded.