Kevin Garnett invited his former Celtics teammates Paul Pierce, Kendrick Perkins, Rajon Rondo, and Glen Davis to appear on his TNT show, "Area 21," on Monday night as part of a Boston reunion that he put together. It’s been 10 years now since KG and his teammates made a title run during the 2007-08 NBA season, so the reunion was meant to serve as a celebration of all they accomplished during their time together. They even had their former coach Doc Rivers, now with the Clippers, call in to share some of his fondest memories of that Celtics team.

There was one former Celtics player who was not in the building with his former teammates, though. Ray Allen wasn’t invited to "Area 21," and at one point in the show, KG revealed why he wasn’t asked to come. If you remember, Allen chose to leave the Celtics after the 2011-12 NBA season to team up with LeBron James, Dwyane Wade, and the Heat to win a title. KG was pissed off about it back then, and it sounds like he’s still pissed off about it now. He talked about Allen’s departure on "Area 21" and suggested that Allen is no longer considered a real Celtic in his eyes.

"People don’t understand that this is real life for us," Garnett said. "The situation with Ray is very sensitive. I think when we all talked about doing this reunion tour, we was talking about guys that we consider loyal, part of this group. Just being honest, my two cents, man. When Ray decided to go to the Heat, I felt like he moved on. He went to pursue another ring. He got another ring—shout to him. And that’s it…It was all Celtics invited to this."

Pierce, who played for the Celtics longer than any of his former teammates, chimed in, too, and said that he was "hurt" by the way the Allen situation played out.

"I was initially hurt by the whole way everything went down," Pierce said. "Like, I don’t have no beef with none of my teammates. I was just hurt on how it went down. We all came together, we talked about it. We talked everyday. We hung out all the time and then, when it was time for free agency—and to each his own—but I thought we formed a brotherhood here in Boston…That’s what I was hurt about when Ray didn’t at least give us a heads up about it."

Allen hasn't responded directly to what Garnett, Pierce, and others had to say. But he did post this on Facebook on Tuesday morning, which looks like a passive-aggressive response to the "Area 21" discussion:

You can hear all of the former Celtics players talk about Allen and the "sour breakup" they experienced from him in the clip above. You can also go here to check out a separate segment from the "Area 21" appearance that features Perkins talking about how Kevin Durant and Russell Westbrook are "back on talking terms."