In 1981, while a student at the University of Kansas, Wallace founded Blue Ribbon College Basketball Yearbook, an in-depth preseason guide, which he edited and published until 1996.
Before joining the Heat, Wallace worked in various scouting capacities for the Trail Blazers, Denver Nuggets, Los Angeles Clippers, and New York Knicks.
Wallace was hired by the Boston Celtics in 1997, with Miami receiving a second-round draft pick to end his contract and allow him to take the new job, and became general manager for the 2000–01 season.
The next season, Wallace made a trade-deadline trade with the Phoenix Suns of top-10 draft pick Joe Johnson for Tony Delk and Rodney Rogers (among others), which would help get the Celtics to their first Eastern Conference finals in over a decade, but the trade became problematic over the long term when Johnson became a major star with Phoenix and Atlanta, while Rogers left the Celtics after Wallace failed to sign him to a contract extension.
He also traded for Vin Baker, who had been signed to a large contract and tied up Boston's salary cap for three years while battling alcoholism.
Wallace stated in an initial press conference that his goal was to one day win a championship with the team and head coach Marc Iavaroni.
[5] He was brought to work in Memphis just days before the 2007 draft, where the Grizzlies chose point guard Mike Conley Jr. with the fourth pick.
Wallace was heavily criticized in NBA circles for trading away the Grizzlies' 27-year-old franchise player, Pau Gasol, to the Los Angeles Lakers on February 1, 2008.