BOSTON >> Doc Rivers will be the next coach of the Los Angeles Clippers if the NBA approves the rare but not unprecedented trade of an active coach, a Boston Celtics official told The Associated Press tonight.

The deal would bring Boston a first-round draft pick in 2015, according to the official, who spoke on the condition of anonymity because the deal couldn’t be final until 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 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.

Rivers took over the Celtics in 2004 in the midst of the longest title drought in franchise history and — with thanks to the New Big Three of Garnett, Paul Pierce and Ray Allen — guided them to the 2008 NBA title. They returned to the NBA Finals two years later, losing to the Los Angeles Lakers 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 trade Garnett, Pierce is also expected to be dealt or bought out, a move that would leave them with only point guard Rajon Rondo as an established NBA star.