"I'm excited," said Laird, who will wear No. 13. "Anyway you can go out and play and help the team, I'm going to do it."
Laird, 24, has played primarily at third and first base in his professional career, though he can play some outfield. In 2012, he hit 31 doubles, 15 home runs and had 77 RBIs in 130 games for Triple-A Scranton/Wilkes-Barre.
"You're just waiting on the call," he said. "Things didn't go the way I wanted them to go in New York, and they designated me [for assignment], but I was just patient, and my agent said other teams like me, and so the Astros took me. I'm excited to be here and see what I can do."
Laird has appeared in 11 Major League games (six starts), all coming in 2011 for the Yankees. He has been a productive hitter in his six Minor League seasons, reaching 20-plus home runs twice and 75 or more RBIs four times.
In 2010 at Double-A Trenton and Scranton/Wilkes-Barre, he combined to hit .281 with 25 home runs and 102 RBIs. Laird, who is the younger brother of veteran Major League catcher Gerald Laird, has been a postseason All-Star three times in his Minor League career, and was named to the Arizona Fall League all-prospect team in '09.