[2] Nwagbuo played high school football at Mount Miguel High School in Spring Valley, California, where he played only one season of varsity football.

As a true freshman in 2003 he started nine games for the Jaguars (seven games at defensive end and two at defensive tackle) and registered 45 tackles, including five sacks and he scored his first collegiate touchdown vs. San Bernardino, recovering a fumble in the end zone.

After taking a redshirt in 2004, Nwagbuo recorded 55 tackles, including 10 sacks, in 2005 and earned second-team All-Foothill Conference honors.

As a senior, Nwagbuo started 12 games at nose tackle after serving as part-time starter on the defensive line in 2006.

Nwagbuo worked at Enterprise Rent-a-Car, but was later signed as a practice player by the San Diego Chargers.