Kevin Garnett welcomed former Celtics teammates Paul Pierce, Rajon Rondo, Glen Davis and Kendrick Perkins during Monday’s Area 21 on TNT. Still, the festivities didn’t truly get started until Doc Rivers showed up.

As the former teammates were getting ready to look back on their time together in Boston, Rivers’ voice started playing in the studio and the now-Clippers head coach appeared on the videoboard. The players had no idea Rivers was coming. They immediately wanted to look back at all the times Rondo clashed with Rivers. It apparently happened a lot.

But given how the “Big Three” was the cornerstone of the 2007-08 Celtics’ title run, there was a noticeable absence at the reunion: Ray Allen.

“It was more than basketball for us… It felt like a sour breakup.” Pierce, KG, Rondo, Big Baby & Perk share their thoughts on Ray Allen. pic.twitter.com/8JYRWmxm0i — KG's Area 21 (@KGArea21) May 9, 2017

Allen left the Celtics after the 2011-12 season to join the Heat where he helped Miami win an NBA title. Garnett and Pierce did not take the move kindly at the time, and some bitterness still resonates with Garnett.

Garnett explained why Allen was not included in the reunion:

“People don’t understand that this is real life for us. 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 cent, 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 added:

“I was initially hurt by the whole way everything went down. 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 — by 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.”

Pierce said he would have taken the move better if Allen had talked to him about it first.