Though the initial barrier to entry for a Conor McGregor vs. Floyd Mayweather boxing match  has been conquered, it appears that crossing the finish line may prove to be the most difficult hurdle. That is according to one insider that has considerable insight into the fight.

Showtime Sports Executive Vice President Stephen Espinoza recently spoke with Yahoo Sports’ Chris Maddox, giving his perspective on where the potential fight currently stands. He has an insider’s knowledge, as Mayweather was under contract with Showtime prior to retiring nearly two years ago.

“The biggest battle in Mayweather vs. Pacquiao was both guys really thinking that the other wanted to do it. That part has happened (with McGregor and Mayweather), so I think the real question, and it is sort of a black box right now, is where is UFC really at on this?” Espinoza said, comparing the difficulties in realizing the monumental boxing match between Mayweather and Manny Pacquiao to Mayweather vs. McGregor.

Conor McGregor vs Floyd Mayweather“(Does the UFC), in fact, want it? Dana – speaking on behalf of, I assume, UFC – is making noises that he’s more open to it, but talk is talk. I haven’t seen a lot of progress either internally in the deal between the two (fighters) or externally, the deal between (the UFC) side and (the Showtime) side.”

Though the fight has long been the stuff of rumor, it has steadily become a realistic endeavor following McGregor’s last UFC fight in November. While speculation initially centered on June or July, the timeframe has moved on to September. 

Espinoza, however, said that even that may not be realistic after the talks, in his opinion, have stalled. He added that if the fight doesn’t happen soon, it may never get done. Fans might lose interest, but more importantly, the 40-year-old Mayweather’s interest might also wane.

“It’s largely at a standstill. There hasn’t been a ton of progress and I think if they don’t move relatively quickly, people may move on. People may tire of it. But it really is something that needs to happen this year or it probably won’t happen,” said Espinoza.

“Floyd’s now on 18 months, two solid years come September, since he’s fought. He’s still in great shape, but at a certain point, he’s not going to do it after a while.”

Mannix and Espinoza both hinted that the hold-up may be primarily on the UFC’s side of the equation. White has publicly stated that he’s not going to try and stop McGregor from taking advantage of such a life-altering opportunity. The UFC, however, has been struggling to get its footing in 2017 following a 2016 that was filled with marquee match-up after marquee match-up. Can the promotion really risk its top star, which is what the two boxing experts questioned?

“We know why Dana’s afraid, Dana’s afraid of his brand getting tarnished with McGregor getting whitewashed in the way that he would,” said Mannix.

“Part of the fear, on the UFC side, is that they’ll never see Conor again,” added Espinoza. “If he makes 50, 60, 70 (million dollars) and then you never (see him again) and he retires in Ireland. There goes (the UFC’s) megastar.”