"I came in through the back way," he said. "I was like, 'Wow, I've never been this way.' That's when I really knew that I'm not a Celtic anymore."
Allen returns to the Garden on Wednesday night as a member of the Memphis Grizzlies. It's his first time playing in Boston as a member of the visiting team. After six years with the Celtics from 2004-10, the 29-year-old swingman shocked Boston last July by leaving in free agency.
"I've got to give a big shout out to [Memphis GM, former Celtics executive] Chris Wallace," Allen said. "He was one of the guys who drafted me when I was here in Boston, and he always had a blueprint for me. He showed me his vision for me down the road. He led the recruiting process."
The Celtics lobbied hard last summer to keep Allen, who emerged as a key defensive stopper in the playoffs against Dwyane Wade, LeBron James and Kobe Bryant. Everyone, from the C's veteran players to their coaches and front office officials, was in touch with him. Allen surprised them all with his decision.
"I did think he was coming back," coach Doc Rivers said. "I was surprised when he didn't. The negotiations got in the way, and that's why he didn't end up coming back. He was really emotional about it; you know Tony. It was tough, because we have a pretty good relationship. That was a tough exchange."
"We shouldn't have to make this thing so much about Tony Allen," Allen responded, downplaying the pain of leaving Boston. "People go through this situation every year. People get traded, people go to other teams, people sign for whatever reason. I made my decision, and it's the decision I've got to live by. I think I did a good job by coming to the Memphis Grizzlies."
Allen has found an increased role in Memphis, starting 22 games this season and seeing a generous share of the touches recently in the absence of injured leading scorer Rudy Gay. He's no longer on a team that's favored to reach the NBA Finals, but the Grizzlies are fighting for a playoff spot of their own. He's enjoying the ride.
"It's been great," he said. "We've got a great group of guys — guys who are determined, ready to do the right things to get where we're going. I like that. This whole ballclub, from the players, to the trainers, to the coaching staff, everybody's ambitious. I like this whole situation."
He's got no hard feelings toward the Celtics except one — he wants to beat them.
"I had some good times here and I had some bad times here," he said. "But for the most part, I'm very excited to be back here. Hopefully we can get a win tonight."
