After playing with the Mavericks from 1999 to 2002, Buckner signed with the 76ers as a free agent. He was waived after two seasons with the 76ers, then signed with the Denver Nuggets. In 2006, he re-signed with the Dallas Mavericks, but after one season, he was traded to the Timberwolves for Trenton Hassell on September 28, 2007. In June 2008, the Timberwolves traded him to the Memphis Grizzlies with Marko Jaric and Antoine Walker for Kevin Love, Mike Miller, Brian Cardinal and Jason Collins.
On July 29, 2011, he joined the Houston Rockets as a player development coach, and he currently serves the team as an assistant coach. Buckner has reached the playoffs three times with the team as part of the coaching staff.