A third-round pick in 2005, the infielder played in five games during the 2009 season -- all in Houston at Minute Maid Park in April.
Through his first four games, Manzella was hitting .286 (four hits in 14 at bats) with one RBI, which he collected on Saturday night against the Phillies.
"So far it's been going good, just trying to get my feet under me, trying to get as much information as I can, especially this first time through the league," Manzella said of his first week as a regular in the Majors. "I don't really know hitters that well. I don't really know pitchers that well. There's only so much you can get off film. So as far as positioning, defensive positioning, sight lines in the new stadiums, stuff like that -- that's the stuff I'll be battling probably for the first half of the year."
Brad Mills, the first-year Astros manager, said Manzella has done a good job making the adjustments that rookies need to make.
"He's getting experience at the plate. and he's going to be gaining experience all year long at the plate and what he can and can't do and he's done a very good job defensively," Mills said. "He's still learning the hitters as we go, but he's made adjustments defensively with the hitters, I think almost each inning as you go along, and that's what you need to do."