"We went 12 hard rounds and I think I made my point last night, I'll say that," he said. "Basically, don't f*** with me. I'm here to help, I'm here to do the best I can for you guys, so don't try to take advantage of me."
Gerard Byrne, an insider in the McGregor camp, later stirred the pot with a suggestive Instagram post of Malignaggi on the ground with the UFC superstar standing over him.
Malignaggi instantly bit back at Byrne for posting the unflattering photo, insisting McGregor's camp release the entire video of the pair sparring.
"I came to help this camp out, not to be exploited, now your (sic) gonna get the truth though. Post (the) FULL UNEDITED VIDEO FROM TUES night," he ranted on Twitter.
I actually beat his ass, 24 hrsoff a flight 2 (sic) lol, which is why I'm saying post the vid, I try not 2 be petty but seems it's late 4 that now."
Malignaggi later released a full statement on Twitter revealing he'd left the camp for good.
"I just wanted to clear the air," he wrote. "I am leaving the McGregor training camp today.
"I came with best intentions and intended to help out. Just the chance to be part of such a big event in this capacity excited me. I believe Conor and I have a mutual respect inside the ting, earn from each other with some good work over two sparring sessions.
"It's some of the other stuff outside the ring and some ways some things were handled in (the) training camp that I didn't agree with (and) made me come to this decision.
"It's not my place to dictate terms in a training camp that is not mine, but it's my place to decide if I want to be a part of it. I will not give away anything tactical that I was in two sparring sessions with Conor. For what it's worth, they have my word.
"The thing s that upset me, though, I will speak about in time. I wish team McGregor well in the rest of their preparations and look forward to being back in Vegas to work fight week on Showtime."
Meanwhile, Floyd Mayweather is busy doing what he does best: boasting about money.
The 40-year-old superstar is hardly short of a quid, but come August 27th (AEST), he will have a scary amount of cash deposited.
The fight was originally tipped to make each combatant $100 million (A$125 million), but "Money" has predicted he'll be walking away with much more than that.
"I mean, am I the highest-paid athlete out there? And just coming back?" he told Showtime.
"We not talking about no contract. We not talking about no contract for no four years, or no contract for no five years. I can do it in 36 minutes. $300 million (A$377 million) or better. In 36 minutes."
If the 49-0 legend is correct, he'll be making more than the average Joe makes in a lifetime in a single minute.
Mayweather made another prediction: the method of Conor's demise.
"I've never been beaten, never," said. "I'm knocking McGregor the f*** out."
A surprising backflip this week saw Floyd agree to fighting with 8oz gloves, significantly lighter than the agreed-upon 10oz mitts - but the move to lighten the gloves appears to have hit a snag. Nevada State Commission executive Bob Bennett said they cannot change the size of the gloves due to rules and regulations in place to protect the fighters' health.
"These regulations are in place for the health and safety of the athletes. Which is of the utmost importance to the commission," he told ESPN.
"Our regulations already outline the appropriate glove size according to contracted weight of a fight."