Conor McGregor accuses Paulie Malignaggi of being "badly concussed" after their sparring session that McGregor claims dented the ego of the former world titlist. (1:52)

LAS VEGAS -- According to Conor McGregor, former world champion boxer Paulie Malignaggi quit as one of his primary sparring partners because he was getting "whupped" during sessions.

Earlier this month, Malignaggi bailed on McGregor's preparations for his Aug. 26 boxing match against Floyd Mayweather, citing multiple reasons. Chief among them, however, was a leaked photo that showed Malignaggi falling backward to the canvas during a 12-round session in Las Vegas.

Malignaggi, 36, denied McGregor knocked him down with a punch, telling ESPN he was "shoved down." He also said McGregor booked a 12-round session one day after Malignaggi flew across the country, in order to catch him while he was jet-lagged.

On Friday, McGregor offered his side of the highly publicized sparring match.

"He tried his best, but he got his ass whupped," McGregor said. "Tell me how his face looked. Tell me how his temple looked. He was badly, badly concussed after those rounds. Badly rattled. He was flattened and knocked down. The ropes kept him up multiple times.

"Sparring partners who were [staying] in the house with him were worried about him. They were ringing us, worried about him stumbling out of the car, incoherent.

"I don't know what happened. At the end of the day, we got in and traded blows, so I respect him for coming in. It didn't go well for him. I don't know why he sprinted out of there. His ego was dented."

UFC president Dana White shed light on the "knockdown" Friday, when he posted a brief clip to social media of the exchange that led to Malignaggi's fall. In the video, McGregor appears to land a left hand shortly before Malignaggi goes down.

Shortly after the clip went up, Malignaggi, who retired from boxing earlier this year, took to Twitter to say McGregor's right hand can be seen pulling him to the canvas. He also challenged McGregor to eventually release footage of all 12 rounds.

"Watch right hand drag me behind my back," Malignaggi wrote. "He's also a southpaw, so it's dragging me toward his lead foot that I trip over. [Half] push, half trip.

"I mean, even tonight's highlights showed what I [had] already said, as a whole he got his ass beat that session, but never will they release [all 36 minutes]."

McGregor, 29, said it was "sad the way it ended," but that it probably wasn't going to end any other way. The UFC champion wanted Malignaggi to "answer" for some of his past comments, regarding McGregor's slim chances of success in a boxing ring.

"In my opinion, this was the best thing for him," McGregor said. "He was looking for a way out. It presented itself and he dived all over it."