While James Harden is on his way to Brooklyn to join the Nets, Kyrie Irving is nowhere to be found after he decided to miss a series of Nets games due to “personal reasons.” The point guard has been missing and reportedly “off the grid” since last week, which appeared to be fine with the team.

All of that changed earlier this week when Kyrie was spotted partying with his father and sister. Now all the attention of the league is on the Nets and their two controversial players. Marc Berman of The New York Post talked with a series of people around the league, who explained what could happen with Irving and Harden when they finally team up in Brooklyn. Kyrie has been labeled as a chemistry killer in the league and Harden’s recent antics in Houston don’t help his image, either.

Unable to comment specifically about the Nets’ new Big 3 because their trade for James Harden is not official, Knicks coach Tom Thibodeau said three superstar scorers on the court together will always have “to sacrifice.’’

But one Eastern Conference NBA scout told The Post that’s easier said than done with the Nets’ freshly bearded beastly trio of Harden, Kevin Durant and Kyrie Irving having formed Wednesday, turning the NBA on its ear.

The scout is most concerned with chemistry between Harden and Irving.

“It’ll be a work in progress,’’ the NBA scout said. “You have literally and statistically two of the five most ball-dominant guys in the league. I watched Houston with John Wall and Harden, and maybe it’s because of the issues, but that didn’t look like a comfortable environment for Harden with Wall dominating the ball. Then you have Durant who I wouldn’t say is ball dominant but certainly needs a lot of touches.’’

“The dynamic between Harden and Irving is the key,’’ the scout added. “Durant can adjust. At Golden State, [Klay] Thompson was not a guy who required the ball. Fewer touches were required for that big 3. Defensively they got worse. Harden doesn’t guard. And they lose [Jarrett] Allen.’’

Tom Thibodeau remembered his times with the Boston Celtics, when they had the famous Big 3 of Paul Pierce, Kevin Garnett and Ray Allen. They made things work out and found success really fast. Thibs believes that superstars always find a way to mesh with other superstars and make each other better.

“There is in the sense that the challenge is the same,’’ Thibodeau said. “I know in Boston when we had Kevin Garnett, Paul Pierce and Ray Allen, that was the big question. I think great players always figure out how to play with each other. They also make other players a lot better. So I think it’s not as hard as people would make it out to be. I think the biggest challenge is the willingness for everyone to sacrifice. If that happens usually the result is very good.’’

Moreover, one NBA scout made probably the most accurate prediction to this new association. He claimed that this could go terribly wrong or it could become the best move the Nets have made in their entire history.

Of course, no one can be sure if Irving is coming back anytime soon, which could make the issue of fitting together the three superstars as moot.

“You can’t count on Kyrie at this point,’’ an NBA personnel director said. “But Harden and KD will be fine. But it will take a minute before everything starts to work.’’

Or explode. As former Wizards and Hawks scout Bryan Oringher told The Post, “It either goes up in flames terribly or they win multiple titles.’’

“Harden is a pretty good insurance policy for Irving,’’ the Eastern Conference scout added.

As they all stated, this could be a huge move for the Nets in their attempts to win the NBA championship for the first time. Kevin Durant is playing great right now and obviously, he would be one of the players that would need to make sacrifices. However, if they find a way to make things work, the Nets are in for a very successful run in the next couple of years.