The Boston Celtics announced Wednesday that Danny Ainge is retiring and coach Brad Stevens is being promoted to president of basketball operations.
The Celtics will start a search for a head coach to replace Stevens and said Ainge will work with the team on the transition through the offseason.
"It was my decision," Ainge said at a news conference Wednesday. "I don't know if there was a moment in time, but like I said earlier, I trust my instincts, and my instincts told me a couple months ago that it was time for me to move on, and that's what's best for us, that's what's best for the Celtics."
Ainge, 62, said he started thinking about the move when he had a mild heart attack in 2019, and he said the last couple of years have been tough because of the pandemic.
"In the bubble and all the rules and scrutiny and protocols that we had to go through has not made the job as much fun," he said.
The moves come a day after Boston's disappointing season came to an end in a loss to the Brooklyn Nets in Game 5 of their first-round playoff series in Brooklyn.
Stevens, 44, who has been coach for the past eight seasons, has been described as worn down with coaching since the bubble and welcomed the chance to make the transition to the front office, sources told ESPN's Adrian Wojnarowski.
"I'm passionate about this group of people, I'm passionate about the team we have, I'm passionate about the people that work in our front office, I'm passionate about our coaching staff, and that's who I've spent all morning with," Stevens said. "I do think I have a good insight into our team as Danny now steps away."
"I'm excited for Brad," Ainge said. "He was born for this."
Owner Wyc Grousbeck, who hired Stevens in 2013, told reporters that he and Stevens agreed "to win banner 18 or die trying."
He said "the idea of Brad taking over became -- it's a natural promotion from within somebody we've worked with for eight years."
Ainge was the architect of Boston's last title team, the 2008 squad featuring Paul Pierce, Kevin Garnett and Ray Allen, and was the third-longest-tenured active lead executive of any NBA franchise, trailing only longtime nemesis Pat Riley with the Miami Heat (1995) and Gregg Popovich with the San Antonio Spurs (1996).
"Helping guide this organization has been the thrill of a lifetime, and having worked side-by-side with him since he's been here, I know we couldn't be in better hands than with Brad guiding the team going forward," Ainge said in an earlier statement.
The Celtics are headed into what is a pivotal offseason for the franchise after Boston finished seventh in the Eastern Conference on the heels of making it to the conference finals three of the past four years. After years of having surplus draft picks and the opportunity to make moves in free agency, the Celtics find themselves without either this offseason.
Kemba Walker, the team's highest-paid player, has two years and $73 million remaining on his deal, and he is coming off a season that saw him miss 29 games -- plus Boston's final two playoff games -- with knee issues. Marcus Smart, the team's emotional leader, is entering the final year of his contract and is extension-eligible. And Evan Fournier, whom Boston acquired at the trade deadline after using a significant portion of the trade exception created when Gordon Hayward departed in free agency last offseason, will be an unrestricted free agent.
ESPN's Tim Bontemps contributed to this report.