Manzella was born in Chalmette, Louisiana and attended Archbishop Hannan High School, and was a three-year starting shortstop.

He was selected to play in the LHSAA All-Star Game, and earned St. Bernard Parish Most Outstanding Player recognition as a senior.

He was named to NCAA Oxford Regional All-Tournament Team after hitting .417 (5-for-12) with three RBIs and two sacrifice bunts, and posted nine putouts and nine assists while helping turn three double plays defensively.

In 2005, he started all 65 games at shortstop and earned first-team All-Conference USA honors after leading the team in batting average (.356), hits (98), stolen bases (21) and assists (171), while tying for first in doubles (24), ranking second in RBIs (62), third in total bases (150), fourth in slugging percentage (.545) and runs scored (58), and fifth in home runs (eight).

In the NCAA New Orleans Super Regional, Manzella started all three games at shortstop, hitting .400 (6-for-15) with two doubles and two RBIs and posted a .417 on-base percentage with a walk.

[2] In 2002, he earned All-Valley League honors as a shortstop and was named to the All Star Game roster as he led his team with nine stolen bases, and finished second on the club in batting average (.313) and doubles (5).

He was promoted to the Lexington Legends in 2006, where he played 99 games and finished with a .275 batting average in 338 at-bats with 7 home runs, 43 RBIs, and 16 stolen bases along with a .956 fielding percentage.

In 2008, Manzella played in 54 games with the Hooks before being promoted to the Triple-A Round Rock Express, where he struggled with a .219 batting average with 0 home runs and 15 RBIs, but had his best fielding percentage at .989.

The Astros signed Manzella to a one-year, $400,000 major league contract on February 15 after having added him to the 40-man roster in November to protect him from the Rule 5 draft.

Manzella was cut from 2011 spring training on March 24, and Matt Downs and Joe Inglett were the backup infielders to start 2011, while Sánchez was the shortstop.

With Clint Barmes established as the starting shortstop, and Sánchez as his backup, Manzella had no role on the major league roster, and on August 10, 2011, he was designated for assignment.

[10] On June 4, 2013, Manzella signed a minor league contract with the Toronto Blue Jays, and assigned him to their Double-A affiliate New Hampshire Fisher Cats.

On August 12, 2013, Manzella signed a minor league deal with the Chicago White Sox, and started at shortstop for the Double-A Birmingham Barons that night.