The Astros released infielder Tyler Greene today. Greene hit .167 and had an OPS of .528 in 18 spring training games with the Astros. If he clears waivers on Thursday, he will become an unrestricted free agent. The move leaves the team with 39 players on the 40-man roster. Drafted by the Cardinals with the 30th pick in the 2005 draft, Greene played the first three-and-a-half seasons of his career with St. Louis. Last August, the Cards traded Greene to the then division-rival Astros.