KISSIMMEE, Fla. — Carlos Pena wasn't signed by the Houston Astros because of his .197 batting average or 19 homers last year. The former Rays first baseman was brought in to be a team leader, the kind he became for Tampa Bay in 2007 when he hit 46 homers for a perennially downtrodden club. One year later, Pena hit 31 home runs to lead the Rays to their only World Series.