Boston Celtics (1996–2003) After Walker's sophomore season, he declared for the
1996 NBA draft and was picked sixth overall by the
Boston Celtics. In the 1996–1997 season, Walker made the All-Rookie First Team and led the team in scoring (17.5 ppg) and rebounding (9.0), as the team had its worst season in franchise history, 15–67. The following season, Pitino was reunited with Walker as the new coach of the Celtics and he made the All-Star team as a reserve while averaging 22.4 ppg and 10.2 rpg. He also scored a career-high 49 points in a loss against the
Washington Wizards. Walker's success led to his appearance on the cover of
NBA Live 99. In the 1998 draft, the Celtics had the 10th pick and chose swing man
Paul Pierce. In the 2001–2002 season, Walker had his best overall season by helping lead the Celtics to a 49–33 record and their first playoff berth in seven years. He was second on his team in scoring (22.0), first in rebounds (9), and first in assists (5.0). Pierce and Walker took the team to the Eastern Conference finals, where they fell to the New Jersey Nets in six games. The next season, Walker made his third All-Star team. On February 20, 2002, former Kentucky teammate
Tony Delk was traded to the Celtics, reuniting Walker with him.
Dallas Mavericks (2003–2004) and Atlanta Hawks (2004–2005) Ten days before the start of the
2003–04 season, Walker was traded with Delk to the
Dallas Mavericks for
Raef LaFrentz,
Chris Mills,
Jiří Welsch, and a 2004 first-round draft pick. On August 8, 2004, Walker and Delk were traded again, this time to the
Atlanta Hawks for
Jason Terry, longtime Hawk
Alan Henderson and a conditional 2007 first-round draft pick. As the pick did not convey, Dallas received cash considerations from Atlanta instead.
Return to Celtics (2005) On February 24, 2005, Walker was traded back to the Celtics in a deal that sent
Gary Payton,
Tom Gugliotta,
Michael Stewart, and a first-round draft pick to the Hawks. (Payton was released by the Hawks and re-signed with Boston for the remainder of the season). Walker started all 24 remaining games for the Celtics, averaging 16.3 points and 8.3 rebounds a game as the Celtics advanced to the playoffs before losing to the
Indiana Pacers in a 7-game first round series. For his second stint with the Celtics, Walker briefly chose to wear the uniform number 88, as his trademark 8 jersey was being worn by rookie
Al Jefferson. Jefferson would switch to number 7 after two games.
Miami Heat (2005–2007) On August 2, 2005, Walker was involved in a five-team, 13-player deal (the largest trade in NBA history) that sent him from the Celtics to the
Miami Heat. The Celtics received
Curtis Borchardt,
Qyntel Woods, the draft rights of
Albert Miralles, and draft picks in the deal. The move reunited Walker with Celtics teammate
Gary Payton. The Heat played Walker mostly off the bench, and he rotated between both forward positions. He finished the season with averages of 12.2 points and 5.1 rebounds a game as the team's main scorer off the bench. Walker also led the team in overall 3-point shots made for the season, and increased his 3-point, free throw and overall shooting percentages. In the playoffs his production would increase, as he would be the third leading scorer for the team, posting 20 points in four different playoff games, including 23 against the
New Jersey Nets in the closing game of the conference semifinals. Miami advanced to the NBA Finals and faced the
Dallas Mavericks, with Walker posting 13.8 points per game in the series as the Heat won the
NBA championship in 6 games. In the title clinching sixth game in Dallas, Walker contributed 14 points and 11 rebounds. Walker's production dipped in the 2006–2007 season as he averaged 8.5 points a game and 4.3 rebounds. The Heat failed to repeat as champions following a first round loss to the
Chicago Bulls.
Minnesota Timberwolves (2007–2008) On October 24, 2007, Walker was traded to the
Minnesota Timberwolves along with
Michael Doleac,
Wayne Simien, a first-round draft pick and cash considerations in exchange for
Ricky Davis and
Mark Blount. On June 27, 2008, Walker was dealt to the
Memphis Grizzlies along with
Marko Jarić,
Greg Buckner, and the rights to
O. J. Mayo, for
Mike Miller,
Brian Cardinal,
Jason Collins, and the rights to
Kevin Love. After appearing in just two preseason games and remaining inactive throughout the opening months of the regular season, he was waived by the Grizzlies on December 19, 2008.
Mets de Guaynabo (2010) and Idaho Stampede (2010–2012) In February 2010, Walker signed with the
Guaynabo Mets, along with former
Chicago Bulls player
Marcus Fizer. Walker was released on April 1, 2010. On May 6, 2010, ESPN reported that Walker was trying to return to the NBA. On December 7, 2010, Walker was acquired by
Idaho Stampede of the
NBA Development League. It was reported in April 2012 that Walker had announced his retirement after two years with the Stampede. ==Personal life==