"They pulled me aside and asked me if I would be interested in joining them," he said Wednesday after signing with the Boston Celtics for the rest of the season. "That probably made the biggest difference of all. They were down there for one of the biggest moments of their careers. ... That meant a lot to me."
The 6-foot-11 Brown last played for the Chicago Bulls, in 2006-07, averaging 6.1 points and 4.8 rebounds in 20.2 minutes. He averaged 9.2 points, 7.8 rebounds and 31.4 minutes per game in his 14-year career, but he has never played a meaningful game in June.
"The final thing that kept me from closing the door was wanting to be a champion. I've had a dream to always want to touch that Larry O'Brien trophy," he said. "There are rare moments and opportunities that come in the league where you have a chance ultimately to be a champion. I think this team gives me that chance."
The Celtics have the best record in the NBA, thanks to Pierce, Allen and Kevin Garnett. Coach Doc Rivers said messing with the team's chemistry was a risk, but "you always take that risk."
Brown's attitude and reputation were part of what attracted the team to him.
"It's a guy we looked at before the year. He just didn't know what he wanted to do and we couldn't wait," Rivers said. "In typical P.J. fashion, he said, 'I want to help. I hope I can help. If I'm a cheerleader every night, I'll do that. If I can play every night, I'll do that. Whatever you need, I hope I can do it for you.'
"I don't know what he can do on the floor yet. We'll find that out. He hasn't played all year."
Brown sat on the bench in street clothes for Wednesday night's game against the Cleveland Cavaliers, getting a big cheer when he was introduced to the crowd in the third quarter. He said he would start practicing Thursday.
"Physically, I'm in shape. But I'm not in NBA shape," he said. "The two biggest things are timing and stamina. It's not going to be overnight, but I'll put in a lot of work and work my tail off. ... When the time comes and my number is called, I'll be ready to go."