Despite the initial excitement about the pairing of former Nets player Jason Kidd and former Nets coach Lawrence Frank, some of those who knew the two were worried how things would play out right from the start, according to various sources around the league and within coaching circles.

One league source told The Post the Kidd-Lawrence union began on rocky footing. After Kidd’s very public courtship of Frank, when the former head coach called to accept the job, he began laying out plans for the team. Frank suggested film sessions immediately.

“I think Jason was like, ‘Whoa, slow down,’ ” the source said. “He had other things to do on summer weekends.”

Multiple reports said Frank took issue with the fact he — as the most experienced assistant on the staff and the only one with NBA head coaching experience — wasn’t tapped to coach the Nets in the opening two games of the season while Kidd served a two-game suspension for pleading guilty to driving while impaired during the summer of 2012.

Though Kidd initially said that decision didn’t have an impact on their relationship, he did say temporarily elevating assistant Joe Prunty to run the team might have been approved by the majority but not his entire coaching staff.

“That was a decision, an idea, that I thought was the right thing to do for the team, and I got different opinions about that,” Kidd said. “Some felt … the majority felt that was the way to go, and that’s the way I went.”

The NBA coaching circle is a small, tight-knit community with few secrets. One opposing team source claimed he “felt it was a bad marriage the day it was announced.”

“Lawrence is a very take-charge guy who works 30 hours a day and expects that of everyone around him,” the source said. “I’m not saying that’s bad, but everybody works differently. I think this dynamic was not good.”

In the wake of being officially “reassigned” by Kidd prior to Tuesday’s blowout loss to the Nuggets in Brooklyn, Frank is in the process of retaining “high-powered” legal counsel, presumably to settle a buyout with the franchise, a league source told The Post.

When the Nets hired Frank — Kidd’s former head coach with the Nets, and who Kidd had publicly pursued to be one of his assistants after taking the job in June — they gave him a six-year deal worth a total of roughly $6 million, according to league sources, making him the highest-paid assistant coach in the NBA.

A former Nets team member said when Kidd played for Frank, “we did what Jason wanted” and that Kidd resented some of the long practice sessions.

As for the mess the Nets now find themselves in, a league source said, from his outside view, “blame can go from top to bottom. At the top, they hired an inexperienced coach. And remember that Lawrence and Jason had a relationship before where essentially the roles were reversed now.”

After Kidd announced Frank will no longer be present at either games or practices, Kidd said Frank will now be submitting daily reports on the team’s games to him.

“I think [Frank] is still working, so there’s no disappointment,” Kidd said after Wednesday’s practice. “So we move on.

“It’s part of the job. He’s working. He’s giving his reports. … So do I miss him? No. He’s doing his job and what I’ve asked him to do.”

When Kidd was asked by The Post following Wednesday’s practice whether he was disappointed things didn’t work out with Frank — given how hard and how publicly he had pursued him and their long-standing relationship prior to taking the job — Kidd said the situation was a learning experience.

“It didn’t work out, … but things happen,” Kidd said. “You learn from them, and you try to get better from every experience and every situation, and that’s all I can go with.”

In making the announcement Tuesday, Kidd also said he no longer would have offensive and defensive coordinators as he did previously, with John Welch running the offense and Frank the defense.

Instead, Kidd said they would all be “just coaches,” and further elaborated on that idea when asked why the previous plan — which Kidd himself had pushed since the summer as a way of replicating the model Larry Bird so successfully worked with in Indiana during his three years as head coach there — didn’t yield the results he envisioned.

“It’s not that it didn’t work, because when we look at the scheme of things, you look at Welchie or [Frank] doing defense or however we had it set up, I think more or less with this decision it brings in everybody’s strengths offensively and defensively. We’ll go with the change of no one strictly being offense, no one strictly being defense, and we’ll got at it as a staff and go from there.”