2006: After leading USC in tackles in 2005, Lua returned for his second season as the starting middle linebacker as a senior in 2006.

2005: Lua emerged from 2005 fall camp as the starting middle linebacker and did a commendable job there as a junior in 2005. Overall in 2005 while appearing in 12 games (he missed the California game with a sprained left knee suffered against Stanford) and starting 11 times (he didn't start against Stanford after getting hurt on the opening kickoff), he had a team-high 66 tackles, including 0.5 sack for minus 1 yard, plus 1 fumble recovery, 2 forced fumbles, 1 interception which he returned 13 yards and 2 deflections. He made 2005 All-Pac-10 honorable mention. He had 3 tackles at Hawaii, a team-best 8 stops against Arkansas, another 8 at Oregon and 3 tackles with an interception (to set up a USC field goal) at Arizona State. He then had a team-best 10 tackles against Arizona, another 10 tackles and a deflection at Notre Dame, 7 stops at Washington and 3 tackles and a fumble recovery (to set up a USC TD) against Washington State. He returned from his knee injury to post 6 tackles with a forced fumble against Fresno State. He had 2 tackles and a deflection against UCLA. He added 6 tackles and forced a fumble against Texas.

2004: Lua was a backup middle linebacker and key special teams player as a sophomore in 2004. Overall in 2004 while appearing in all 13 games, he made 13 tackles, including 1 for a loss. He had 2 stops against Virginia Tech and Oregon State. He missed some of 2004 spring practice while recuperating from a knee injury.

2003: Lua hoped to push for the starting middle linebacker job as a sophomore in 2003. But he missed 2003 spring practice while recuperating from a knee injury suffered late in 2002. He then played briefly against BYU but reinjured the knee, forcing him out for the rest of the 2003 season (he had mid-season surgery). He was able to redshirt because of the early injury.

2002: Lua served as an often-used backup middle linebacker and played on special teams as a freshman in 2002, his first year at USC. Overall in 2002 while appearing in 11 games (all but Arizona State), he made 13 tackles, including a 14-yard sack, forced a fumble and recovered a fumble. He had 2 tackles against Oregon State, Washington State and UCLA. His sack was at Colorado (which caused a fumble that USC recovered to set up a TD) and his fumble recovery was at Kansas State. He tore ligaments in his right knee during bowl practice, had surgery and was sidelined.