The Boston Celtics shook up their front office on Wednesday, a day after they were eliminated from the playoffs, with president of basketball operations Danny Ainge retiring and coach Brad Stevens moving up to the front office to replace him.

The moves game about 12 hours after the 17-time NBA champions lost to the Brooklyn Nets in Game 5 of their first-round playoff series. The Celtics, who reached the conference finals in three of the previous four seasons, had flirted with a top-four seed in the East for much of the season before stumbling into the play-in round.

Celtics staff were informed Wednesday morning of the moves, which were first reported by ESPN and The Athletic.

Ainge won NBA titles with the Celtics in 1984 and '86 and took over as the team president in 2003. He was voted the league's top executive in 2008, when Boston won its 17th championship — a league record that has since been matched by the Los Angeles Lakers.

"Helping guide this organization has been the thrill of a lifetime," Ainge said in a statement. "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."

Stevens has taken the Celtics to the playoffs in seven of the eight years since he left Butler for his first NBA coaching job. He is the fourth-winningest coach in team history, behind Red Auerbach, Tommy Heinsohn and Doc Rivers.

He said the search for his replacement will be "wide-ranging and comprehensive."

"I love the Celtics, and know the great honor and responsibility that comes with this job," he said. "I will give it everything I have to help us be in position to consistently compete for championships."

Stevens did not allude to the looming moves in his final news conference following the loss in Brooklyn, though he pointed to Boston's future.

"We didn't play perfect basketball, but we showed a lot of growth in the past few weeks, both individually and at times collectively," Stevens said. "And so, there's stuff to build off of. But at the same time, the task is tall and if you want to be in the mix, then you've got to be better than we were."

After reaching the conference finals last year, losing to Miami in the NBA bubble, the Celtics struggled with injuries and COVID-19 this season, losing 10 of their last 15 games to fall to seventh in the East. They beat Washington in the play-in game but could only manage one win against the Nets and former Celtic Kyrie Irving.

"You can improve through continued development and the right work ethic and doing a good job with the developmental stuff," Stevens said. "Then, obviously, there is the ability to acquire people. This team that beat us is a very good team. There are very good teams across the East and we have to get better. We never got a true look at this team this year, but I think we have enough information that shows that we need to get better."