Shams Charania of The Vertical passed along the news. Brian Windhorst of ESPN previously reported Pierce was willing to extend his contract deadline if the Clippers wanted an opportunity to move his salary as part of a potential trade.
The 39-year-old Boston Celtics legend played a limited role throughout his final season in Los Angeles. That said, his career resume includes 10 All-Star Game selections and an NBA Finals MVP award from the Celts' triumph in 2008.
He announced his intention to sign a contract with the Celtics to officially retire as a member of the organization, which the Clippers' move will make possible. Celtics owner Wyc Grousbeck also confirmed the franchise will retire his No. 34.
The Clippers didn't need to include Pierce's salary in the deal in order to make it work under the salary cap, though.