After dropping Kyrie Irving back into the mix with Kevin Durant and newcomer James Harden, Brooklyn has the potential to become an offensive juggernaut. But the other end of the court is every bit the issue it was expected to be.

So far there’s been no D in Brooklyn.

Watching the Nets debut their Big Three but lose 147-135 to offensive-challenged Cleveland, it’s not quite fair to say they’ll go as far as their defense takes them. More like they’ll only get as far as that sieve-like defense allows them to go.

“We are more or less responsible for putting these pieces together and making it work. Offensively it clearly wasn’t enough, (but) we still needed to get stops on the other end,” Irving said. “So that’s going to be the tale of our season, is how committed are we to that end of the floor moving forward.”

Unless they want it to be a tale of the superteam that failed, they’ll need to worry more about getting stops than buckets. Despite having several limited individual defenders, they must learn to play better team defense to reach their goals.

The 147 points they allowed Wednesday are the most in the NBA so far this season. Granted, they came in double-overtime; but against a Cavs team with the league’s worst Offensive Rating, and minus Kevin Love and Darius Garland.

Brooklyn also surrendered 141 to Atlanta on Dec. 30, and sits 22^nd in Defensive Rating going into Friday’s rematch with the Cavs.

“Some great glimpses; we started off the game very good. Just the entire game, we’ve just got to find a way to get stops when we need to,” Harden admitted. “Offensively, statistically they’re not a very good team, but they made some shots, so we’ve just got to watch some film and get better and chip away.

“We’re still early in this process, it’s early for all of us. We’ve got a long way to go.”

The Nets’ Big Three combined for 96 points in their debut; but Brooklyn also had a horrid 122.4 Defensive Rating with the trio on the floor.

There are concerns about roles, rotations and shot distributions, Irving coming off a seven-game layoff and putting up 28 shots – more than Durant and twice as many as Harden. But the offensive IQ between the trio, coach Steve Nash and assistant Mike D’Antoni will likely sort that out. The defense engenders a lot less faith.

Brooklyn allowed .514 shooting on Wednesday, 20-of-40 from deep and 6-of-7 in a 20-point second overtime.

They were helpless as Collin Sexton poured in 42 points, including five in the first OT and 15 in the next.

“We had breakdowns all over the place; so we’ve got a lot of work to do. We know that,” said Nash. “We know that we have a very offensive team right now, so we have to find ways to defend, to get connected, to be on the same page, and that’s going to take some time.

“It’s definitely early as far as this new group learning to defend together and how we can be effective defensively. That’s got to be one part of our game that we’re going to focus on the most going forward.”

Can focus fix this?

A Harden-Irving backcourt was never going to be stout defensively. Dealing Jarrett Allen robbed them of their rim protection, underscored when they allowed 64 points in the paint Wednesday while he blocked four of shots for his new team.

Yes, fatigue played a role as the Nets starters looked gassed in the second OT. But guard Bruce Brown, their only stout perimeter defender, logged just 7:01.

While there were tired legs, and players still getting used to one another, there is also a personnel problem that can’t be ignored. And may not be easily solved.

“All the above,” Nash admitted. “That doesn’t mean that because we have offensive personnel that we can’t be better, improve our communication, get guys in the better condition. We feel positive in that we can improve defensively; but it’s definitely got to be a priority.”

Make that the priority.