The September showdown between the undefeated boxing champion Floyd Mayweather Jr. and rumored opponent, Andre Berto, could still be a pay-per-view event (PPV).

A source who is privy about the current negotiations told Boxing Scene that there's a 98 percent chance that Mayweather's next match will be set with a PPV subscriptions arrangement.

PPV vs. Network TV airing

The great probability that the fight will not be aired for free on network television may have been hinted by Stephen Espinoza, the Executive Vice President and General Manager of Showtime Sports.

"Network television operates under a different timetable, particular in terms of selling ads. From network TV.... we're talking six, eight, ten months in advance - and not six, eight or ten weeks in advance [like a pay-per-view event]. In some ways selling ads to a one-off event, even if its the biggest one-off event that boxing has to offer, is a challenge for network television," Espinoza told Boxing Scene.

The outlet explained further that even though the upcoming match is a much-anticipated event, marketing efforts will be a great challenge since usually, advertising slots on network TV are bought months before. The fight is happening on Sept. 12, just less than two months from now and with no definite and official viewing arrangement yet for for the viewers.

It must be noted that Mayweather has been very vocal about his farewell fight, especially after his May 2 clash against the Filipino boxing icon Manny "Pacman" Pacquiao at the MGM Grand Arena in Las Vegas.

CBS or whichever partner network proposed the September bout to be aired via free TV, should have already sold a great number of ad slots for an event to happen in three and a half months, Boxing Scene opined.

Official announcement to be released soon

Still, the details surrounding the fight will be announced soon, according to Espinoza.

"Personally I believe that it will be announced this week, possibly next week. But we're getting close," Espinoza said.

So far, the details available are the date and venue of the bout, which are Sept. 12 at the MGM Grand Arena in Las Vegas.

Even Mayweather's opponent, whom TMZ Sports reported to be officially Berto, is not yet "finalized."

"Nothing has been finalized yet. As soon as everything is finalized, an announcement will come immediately," Espinoza said.

Even Berto's trainer, Virgil Hunter, is saying that he can't really say with finality if his boxer will truly face Mayweather in September.

"So far everything remains speculative. The reality is we do not know if we're going to fight him. The fight has to be made official in order to speak about it," Hunter told ESPN Deportes.

However, official or not, Berto is preparing hard for the fight, as seen in his posts on his Twitter account.