He then transferred to Oak Hill Academy in Mouth of Wilson, Virginia, and was rated by Bob Gibbons to be the best prep player of the class of 1995.

Mercer had a very successful collegiate career, having been an All-American and all-Southeastern Conference player at Kentucky, and part of a national championship team his freshman year.

Some felt this was just a ploy to scare the other teams away from him so as to increase the likelihood of Mercer being available by the time the Celtics got an opportunity to make their draft selection.

[5] Despite Mercer's 16.8 points per game in 2001–02, he was traded midway through the season alongside Brad Miller, Ron Artest, and Kevin Ollie to the Indiana Pacers for Jalen Rose, Travis Best, Norman Richardson, and a second-round draft pick.

[citation needed] In 1997, Mercer and fellow former Celtic player Chauncey Billups were accused of sexually assaulting a woman at the home of teammate Antoine Walker.