He played one season for the San Francisco 49ers and two for the Minnesota Vikings of the NFL, and one for the Los Angeles Avengers of the AFL.
[3] His parents moved after three of Serwanga's uncles were killed under the regime of Idi Amin for being wealthy; his father Patrick, sold his possessions in exchange for plane tickets to bring the family to the U.S.[3][5] Patrick himself had nearly been killed by Amin's regime, surviving an attempted murder by jumping from his moving car.
[3] Serwanga's father worked washing dishes to provide for the family, who lived in a small apartment with only two beds.
[5][6] He and his brother played football while attending Sacramento Charter High School, where they both were cornerbacks, with Wasswa being a starter.
[10] The twins both started at Sacramento State as freshmen in 1994, but transferred to the Pacific Tigers following one season when the school initially decided to drop football.
[11] They saw significant playing time with the Tigers in 1995, as both appeared in eight games (sitting out several due to transfer rules), with Wasswa totaling 23 tackles and two interceptions.
[13] They had to transfer again, with Wasswa committing to the UCLA Bruins while Kato went to the California Golden Bears, the first time the twins were on separate teams.
"[12] In his first year at UCLA, 1996, Serwanga was a backup to Anthony Cobbs at the roverback position (a type of strong safety), also being a member of the kickoff unit.
[12][14] The twins faced off against each other when UCLA played California, with the News-Pilot describing them as being a "mirror image" of each other, as both were the same height (5 feet 11 inches (1.80 m)) and weight (190 pounds (86 kg)).
[4] Serwanga helped UCLA compile a 9–2 record and reach the 1998 Cotton Bowl Classic, where they played against the Texas Longhorns.
[20][32] He also started in the season finale, against the Indianapolis Colts, covering star wide receiver Marvin Harrison.
[32] In the game, he totaled 12 tackles, a forced fumble and a pass deflection, as Harrison caught 12 receptions for 109 yards and three touchdowns.
[20][32] Serwanga also started in the Vikings' two playoff games, totaling 11 tackles and four pass deflections before the team was eliminated 41–0 by the New York Giants.