"(Pierce) said, 'You know what, from now on I ain't gonna raise my voice at nobody,'" Allen recalled. "He said, 'If I've got a problem, we're putting on the gloves' ... He was like, 'I've got gloves for everybody because I'm tired of everybody bickering.' Just in case, he had all sizes."
Allen selected Davis as his opponent, which turned out to be a mistake.
"I remember me trying to get my first little couple of swings at him, and all I can remember is Glen Davis knocking me out. Boom. I fell," Allen said. "They said, 'Awww, he's knocked out.' They all started laughing and running.
"That was probably one of the most weird ways to bring in camaraderie and bring in love and togetherness. But it was funny, man."
Allen played for the Celtics from 2004-10 and won a championship with the team in 2008 before joining the Memphis Grizzlies.