Mack was selected in the fourth round (111th overall) by the Cincinnati Bengals where he played for four seasons.[4] As a rookie, he started four games and recorded one interception. In his second season, he became the team's primary return specialist, recording 1,165 return yards for the season. In 1999, he recorded a career high 1,382 return yards and earned a trip to the 1999 Pro Bowl along with teammate Corey Dillon. In 2000, Mack recorded 1,036 return yards in his final NFL season.
After three years out of football, Mack spent one season with the Louisville Fire of af2. That was followed by two season with the San Jose Sabercats of the Arena Football League (AFL). He set the AFL rookie record for consecutive Defensive Player of the Week honors.