Paul Pierce, Rajon Rondo and Ray Allen on the Celtics’ bench during happier times in 2011. (Charles Krupa/AP)

Bulls point guard Rajon Rondo is busy planning a reunion of the 2007-08 Celtics at an undisclosed location abroad this summer, but shooting guard Ray Allen, who averaged 17.4 points per game for the team that won Boston’s first NBA title in 22 years, won’t be receiving an invite.

“I asked a couple of the guys,” Rondo told The Undefeated’s Marc J. Spears when asked why Allen wasn’t included in the reunion plans. “I got a no, a no head shake.”

Grudges apparently don’t die easily in the NBA.

In June 2007, the Celtics traded Wally Sczerbiak, Delonte West and the No. 5 pick in the NBA draft to Seattle for Allen. A month later, Boston acquired Kevin Garnett in a blockbuster deal with the Timberwolves. The duo, along with veteran forward Paul Pierce and Rondo, the Celtics’ second-year point guard, guided Boston to a 66-16 regular season record and a 4-2 series win over the Lakers in the NBA Finals.

The Celtics returned to the Finals two years later, but Allen’s relationship with that group forever changed in the summer of 2012, when he turned down a two-year offer to remain in Boston to sign a three-year, less lucrative deal with the Miami Heat. Spears reports that Allen, who won a championship with the Heat in 2013 and played his last game in 2014, has been estranged from his former Celtics teammates ever since.

“It will be a long story about that, but it is what it is,” Rondo said. “I don’t know a good analogy to put this in. It just wasn’t the greatest separation. It wasn’t the greatest thing that could’ve happened to us as a team, a bond. We were at war with those guys [Miami]. To go with the enemy, that’s unheard-of in sports. Well, it’s not so unheard of. It’s damn near common now.”

Garnett ignored Allen when he went in for a high-five early in the 2012 season and said he longer had Allen’s phone number. During a 2015 interview with ESPN’s Jackie MacMullan, Pierce said that he hadn’t spoken with Allen since he joined the Heat, but also noted that he wasn’t particularly close with Allen during their five years as teammates in Boston.

“It was a weird relationship,” Pierce said. “We were all good friends on the court, but Ray always did his own thing. That’s just the way Ray was. Even when we were playing together, we’d be having a team dinner and Ray wouldn’t show up. We’d go to his charity events but Ray wouldn’t show up to somebody else’s. I called him on it. I said, ‘Man, Ray, we support all your stuff but when we ask you, you don’t come to ours.’ I remember when Rondo re-signed with Boston, we had a little dinner at a restaurant and Ray didn’t show up. I know Ray probably didn’t like Rondo that much, but it wasn’t a fact of not liking somebody. You don’t have to like everybody you play with — it’s a matter of showing support. Rondo probably didn’t like Ray either, but he came to Ray’s functions to show, ‘Hey, we’re together in this.'”

Last November, Pierce told Spears that Celtics players considered Allen’s decision to join the Heat “a betrayal.”

Leon Powe, another member of the Celtics’ title-winning 2008 team, told Spears his “preference is that Ray is extended an invitation.”

Despite keying Boston’s Game 2 win over the Lakers with 21 points off the bench, Powe’s opinion probably doesn’t carry the same weight as some of his teammates’s thoughts on the matter.