When the Nets come back off the road, they’ll welcome reigning champion Boston to Barclays Center.

And surely hordes of green-and-white clad fans as well. 

The crowd promises to be electric.

And surprisingly huge. 

And unsurprisingly split. 

In the midst of this tanking season, people around the Nets have privately admitted surprise at the size of the crowds they’ve continued to draw — attendance on par with their star-studded Big 3 campaigns of years ago.

They’re pleasantly surprised to have been wrong: You can rebuild in New York. 

Now comes the long-range task of converting all of those paying basketball fans into proud Brooklyn fans.

That’s going to be an extended process, growing young kids into lifelong Nets fans, getting ingrained with the Brooklyn community at-large and, perhaps most of all, building a winning team again. 

Cam Thomas, shockingly one of the longer-tenured Nets despite still being just 23, has seen steps in the right direction since his 2021 arrival.

Baby steps, but steps nonetheless. 

“I’ve noticed a difference in the vibe from then to now, that they seem more in tune with how we are doing,” Thomas told The Post before the Nets’ 116-110 loss to the Bulls Thursday night in Chicago. “It’s still the same somewhat, but they’re definitely more in tune with us. It’s not as bad as it was my rookie year. 

“I mean, I get it: You’ve got these Hall of Famers coming into town on some of these teams, so it’s very exciting. But then they still come out to our home arena. The guys hope that we get to win. But it’s not as bad as it used to be. It used to be real bad, for sure. So it’s definitely gotten better.” 

Well, the attendance certainly has.

Even in a down year. 

Just look at the past two home games.

The Nets drew a record 18,413 on March 6 against Golden State, their biggest crowd ever in Brooklyn.

Their next home game four days later against the Lakers drew 18,215 despite a seven-game losing skid. 

“We’ve been facing it for a while now,” Cam Johnson shrugged. “And at the end of the day, we still do have fans in here. Maybe some are pulling for the other team, but this is still our home court. This is still where we play. This is still where we’re comfortable. 

“So we don’t worry about that; we just go out and compete. And on one hand, it’s enjoying the atmosphere. One thing we want to do as basketball players, as competitors, is play in the best atmospheres possible. Even though the [recent] Warriors game you had a lot of blue and yellow out there, there was still a great atmosphere that we love to compete in.” 

But the crowds have been solid all season despite the Nets tanking.

They’re averaging a fraction under 17,400 — yes, just 25th in the league, but 1) over 98 percent capacity, and 2) solid compared to even some of their better years. 

It’s close to last season’s 17,584, and more than the 17,354 they pulled in 2021-22, when they had Kevin Durant, Kyrie Irving and James Harden as draws. 

Of course, the Nets employ markdowns and promotions.

And they rely heavily on walk-ups — which in New York largely consists of tourists priced out of the Garden. 

But the gate shows the Nets’ brain trust was mistaken in its earlier belief that teams can’t rebuild in New York.

That’s important because it could embolden them — if they can’t land the star offseason targets — to extend the tank for another year.

After all, the crowds may not be all Nets, but they’re large.

And lively. 

“It’s fun to see. I feel like in those times and in those moments, whenever us as the Brooklyn Nets are winning, those jerseys are kind of cheering for us. So I feel like [it’s] a good environment for us,” Keon Johnson said. “Only thing I can say is it’s just crazy and loud.”