Two of the biggest public names linked to the Professional Fighters Association (PFA) have cut ties with the organization.

Lucas Middlebrook, the PFA's labor lawyer known by many in MMA circles as Nick Diaz's attorney, and UFC fighter Leslie Smith will no longer be involved with the PFA after information of a possible board of fighters was recently leaked to the media, they told MMA Fighting.

Baseball superagent Jeff Borris and Middlebrook announced the formation of the PFA at a press conference in August. The group has set out to unionize UFC fighters in an effort to balance the pendulum between promotion executives and the talent. The UFC was sold to talent agency powerhouse WME-IMG for more than $4 billion in July.

Smith, who was one of the few UFC fighters public in her support of the PFA, told MMA Fighting that she helped compile a list of potential fighters to target for a spot on a "fighter board." Those fighters, Smith said, told her they might be interested, but had not committed to anything.

Smith said all talks with those fighters were meant to be confidential and she was shocked when their names — and other pertinent info about the PFA — ended up in an article on MMAjunkie.com earlier this month.

"I promised confidentiality to everyone I talked to," Smith said. "And Jeff promised me confidentiality and Lucas promised me confidentiality, too."

After the leak, Smith said she asked Borris about the situation. In the process of doing so, Smith said Borris told her that he had put together an advisory board of MMA agents. That news further upset Smith, because she hadn't intended for agents to be part of the unionization process.

After a few weeks of thinking it over, Smith said she told Borris that she would not be part of the PFA anymore last week because of the breach of trust.

"I didn't want to do it immediately, because I know the media and the UFC and really everybody else who have been following along have been laughing at us about the lack of unity in an effort to try and unify people," Smith said. "It's ridiculous and I totally agree that it's ridiculous and it's embarrassing. And I didn't want to contribute to that at all. I see the benefits of a unified front and I would like to be part of a unified front."

Smith said she applauds Borris for attacking the issue of a fighter union "with gusto," but she no longer felt comfortable after what she thought to be confidential information was compromised. Smith wrote a letter of apology to those affected by the leak and anyone else she introduced to Borris during her relationship with the PFA.

Middlebrook said he felt similar, calling it a major "setback" with regards to gaining the trust of fighters.

"I still don't know who released the information," Middlebrook said. "It troubled me because the one thing that I was advocating for, which was an executive board of fighters, was because you could gain some solidarity and some trust and that simple release — or not keeping that information close to your hip — was a setback and it did exactly the opposite of what I was advocating we should do, which was put fighters in decision-making roles."

Middlebrook said he had been pushing for an interim executive board of fighters, which was coming together. But the leak caused things to fall apart. Smith's decision to leave the PFA also contributed to his choice to depart, he said. Middlebrook said he and Smith had worked closely together in the unionization effort since August.

"To have your biggest fighter proponent since the beginning lose faith, I just decided it wasn't the right organization for me to be associated with any longer," Middlebrook said.

Smith and Middlebrook both said they are still interested in being part of the fight to unionize UFC athletes, just not with the PFA.

Borris told MMA Fighting that he doesn't know how the information and names leaked, but said he does not believe the series of events makes the PFA untrustworthy.

"I never released any information regarding anybody's name to the public at any time," Borris said. "I've been asked a million times by lots of reporters on numerous occasions. I've always said I cannot and I will not release any names."

Borris, who represents the likes of Barry Bonds and Rickey Henderson in baseball, said Smith has a "disdain" for agents and that skewed her judgment of the role of an agent advisory board.

"I told her that if you look at every major sport — baseball, basketball, football, hockey — they have agent advisory boards in each sport," Borris said. "And there's lots of good agents, too, and they have their finger on the heartbeat of the industry. I need them and I will rely on these agents to help guide me as far as what issues they see as being important to them in collective bargaining."

Borris said the PFA plans on moving ahead without Middlebrook and Smith and he doesn't see the situation being more than a speed bump.

"I don't look at it like that," Borris said. "I have many other fighters who have greater stature in the fight game who have committed to me. There are many labor lawyers who are vying for that position."

In order for UFC fighters to unionize, 30 percent of the roster will need to sign solicitation cards. If that process is successful, Borris — or another possible union leader — can go to the UFC to see if they will voluntarily recognize a union. If the UFC says no, the cards can be brought to the National Labor Relations Board (NLRB) and an election will be held. At that point, 50 percent of UFC fighters plus one are needed to elect a union and executive director.

There are also other organizations outside the PFA attempting to unionize fighters.

Borris would not say how many cards have been signed thus far and isn't putting a timetable on the process.

"It's easier than I thought regarding convincing the fighters about the need for a union," Borris said. "It's harder than I thought as far as trying to eradicate the fear that they have. I had no idea to the extent that the fighters are this fearful of the UFC."