Mauck was a star baseball and football player at Jasper High School in Jasper, Indiana, and, as a pitcher, center fielder and third baseman, helped lead the high school baseball team to state baseball championships in 1996 and 1997. He also led the football team to the state finals as a quarterback and defensive back in 1995. He originally committed to play quarterback for head coach Nick Saban at Michigan State out of high school in 1997. Ultimately, however, he chose to sign a Major League Baseball contract with the Chicago Cubs after he was drafted in the sixth round of the 1997 MLB Draft, instead of playing college football. He would play on the minor league level in the Cubs organization for three years, before returning to college to play football.
Mauck accepted an offer to play football at LSU in 2000. LSU was coached at the time by Nick Saban, the same coach who recruited him to play football at Michigan State three years earlier. Saban had just accepted an offer to come to LSU, and was looking for depth at the quarterback position. Mauck was redshirted during the 2000 season, and saw limited action during 2001 regular season. His first significant action came during the 2001 SEC Championship Game, when he came off the bench to replace injured starting quarterback Rohan Davey. Mauck would run for two touchdowns, leading the underdog Tigers to a come-from-behind 31-20 victory over the heavily favored #2 Tennessee Volunteers.
In 2002, Mauck entered the regular season as the starting quarterback, beating out Marcus Randall and Rick Clausen. He led the Tigers to a 5-1 start, but was lost for the season with a broken foot during the sixth game. The Tigers slumped after the injury, finishing the season with an 8-5 record.
Mauck decided to go pro after the 2003 season, and he was selected in the 2004 NFL Draft by the Denver Broncos with the 225th pick in the 7th round. He made the roster, but did not appear in any games in 2004. In 2005, he signed with the Tennessee Titans. He appeared in two games during the season, including one start in the final regular season game of the year, a loss to the Jacksonville Jaguars.