Kazuo Matsui
Manzella was the Opening Day shortstop with the Astros in 2010, and Jeff Keppinger also got time there when he wasn't at second base. He went 13-58 (.224) with 3 RBI in April. He hit his first major league home run, a 2-run home run off of Rodrigo López of the Diamondbacks, on May 5, putting the Astros on top 2-1 in a game they eventually won 3-2. He hit .192 (14-73) with 5 RBI in May. When the Astros placed Kazuo Matsui on waivers on May 20, Keppinger took over full-time at second base, making Manzella the full-time shortstop. He was hitting .224 (13-58) in June before he fractured his left index finger on June 22 when Nate Schierholtz slid into it trying to steal second base. The Astros recalled Oswaldo Navarro to take over at shortstop, but they eventually acquired Ángel Sánchez to take over on July 1. He rehabbed at Corpus Christi and Round Rock for 11 games total before returning on August 19. He finished the year splitting time with Sánchez at shortstop. In 83 games with the Astros, he hit .225 with 1 HR, 21 RBI and a .973 fielding percentage.