not unprecedented trade of an active coach, a Boston Celtics official told The Associated Press on Sunday night.
The deal would bring Boston a first-round draft pick in 2015, according to the official, who spoke on the condition of anonymity because it is pending a trade call with the NBA office. Rivers, who had three years and $21 million left on his contract with the Celtics, must also reach an agreement on a new deal with the Clippers.
Celtics spokesman Jeff Twiss said the team had no announcement.
The tentative agreement on Sunday wraps up weeks of haggling over the deal and frees Rivers from presiding over the dismantling of the team that won the franchise's record 17th NBA title in 2008.
The Celtics and Clippers have also discussed sending Kevin Garnett to Los Angeles in a package with Rivers for draft choices, center DeAndre Jordan and point guard Eric Bledsoe. But NBA commissioner David Stern nixed those talks this week, saying teams aren't allowed to trade active players for a coach.
A deal for Garnett could still happen, but the teams would have to convince the league that it was a separate deal. The 37-year-old big man has a no-trade clause in the contract that will pay him 23.5 million over the next two years, but it is believed he would waive it to be reunited with Rivers on the West Coast. He has also discussed retiring.
Boston could also cut ties with Paul Pierce, the longest-tenured member of the team, who is due to earn $15.3 million next season; he could be bought out for $5 million. Pierce will be 36 by the 2013-14 opener and showed signs of slowing down this season, when he averaged the fewest minutes per game in his career.
Rivers took over the Celtics in 2004 in the midst of the longest title drought in franchise history and - with thanks to the "Big Three" of Garnett, Pierce and Ray Allen - guided them to the 2008 NBA title. They returned to the NBA Finals two years later, losing to the La Lakers Jersey in seven games.
But the Celtics have regressed steadily since then, twice failing to get past the Miami Heat in the Eastern Conference playoffs. This year they finished third in the Atlantic Division - they had won it five straight times - and lost to the New York Knicks in the first round.
That convinced many that it was time to rebuild - a process Rivers was reluctant to supervise. If the Celtics unload Garnett and Pierce, that would leave them with point guard Rajon Rondo as their only established star.
Rivers had the second-longest tenure of any NBA coach to San Antonio's Gregg Popovich, compiling a 416-305 record in Boston that was the third-most wins in franchise history behind Red Auerbach (795) and Tommy Heinsohn (427). He also spent four-plus seasons with the Orlando Magic and is 587-473 in all.
Trades for coaches have occurred about a half-dozen times in NBA history, most recently in 2007 when the Heat received compensation for allowing Stan Van Gundy to go to the Orlando Magic.
In 1983, the Chicago Bulls Jerseys sent a second-round draft pick to Atlanta as compensation for coach Kevin Loughery. The Hawks used that pick to take Glenn "Doc" Rivers.
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