Aldo (25-1) was of course supposed to fight McGregor (18-2) on that multimillion-dollar UFC 189 event, but was forced to pull out less than two weeks before with a rib injury. Mendes agreed to fill in on short notice.
Had McGregor lost, it would have spoiled the most lucrative matchup in Aldo's 11-year professional career. Whether he liked it or not, Aldo was heavily invested in that fight's outcome -- but instead of watching it live, he went to a friend's house to watch a Brazilian soccer match.
The seven-time defending champion says he was so convinced McGregor would win, he didn't need to watch it play out.
"I knew before that fight happened, Conor won," said Aldo, through a translator. "Chad didn't have the time to train hard. He was hunting and not in the gym (before the fight)."
McGregor claimed an interim championship in the win against Mendes (17-3) and the UFC has re-booked the fight between he and Aldo as the main event of UFC 194 on Dec. 12 in Las Vegas. Aldo says the rib injury that forced him to withdraw from the initial meeting has healed well and is a non-issue when it comes to the re-scheduled date.
In addition to canceling the biggest fight of the year, Aldo's rib injury stirred up plenty of headlines this summer -- as UFC president Dana White stated Aldo suffered a "bruise," while the fighter and his camp said it was a broken bone.
Aldo says he met with White late last month in Rio de Janeiro, where the two sides ironed out what Aldo now refers to as a "miscommunication." He says he does not feel disrespected by any comments White made.
"I had dinner with Dana in Brazil," Aldo said. "Both sides talked a lot about this and Dana didn't disrespect me. It was just a misunderstanding about the communications. I have no problem with Dana or (UFC CEO Lorenzo Fertitta)."
With the supposed rift between Aldo and the UFC settled, focus has returned to Aldo's attempt at an eighth title defense, which would place him two shy of former middleweight champion Anderson Silva's all-time record.
Fighting out of Nova Uniao in Rio, Aldo says he will not change any aspect of his training regiment out of fear of injury. He said Fertitta gave him some form of light, protective upper body wear that he'd put to use, but that's it.
One major aspect of the championship fight being delayed is that it will now take place under a new anti-doping rule, which does not allow fighters the use of IV rehydration after weigh-ins, a relatively common practice in MMA.
At a press conference with Brazilian media last month, Aldo was quoted as saying he'd simply ignore the rule and use an IV anyway -- a violation that could warrant a two-year suspension.
Aldo's longtime coach Andre Pederneiras says those comments were meant to be a joke and doesn't anticipate Aldo to have any trouble making weight under the new rules. Aldo has used IV rehydration regularly since 2013.
"I think it's much harder for Conor to make weight than for Aldo," Pederneiras said. "Aldo just cuts 15 pounds. How much does Conor cut? I prefer both guys, after weigh-in, have a camera with them 24 hours -- see what both are doing. I know (Aldo won't use an IV) for sure, but I don't know Conor. He probably cuts 30 pounds. Who do you think needs an IV more, Aldo or Conor?"
Barring another injury setback, the 145-pound title unification bout will produce an enormous amount of business. UFC 189, even after Aldo's removal, drew a reported live gate revenue of $7.2 million, setting a new record in the U.S.
McGregor's manager, Audie Attar, previously predicted to ESPN.com a fight between the Irishman and Aldo would produce 2 million pay-per-view buys.
It's no surprise then that Aldo, who hasn't lost since November 2005, said he wouldn't mind facing McGregor more than once.
"I prefer it would happen more times because it puts more money in my pocket," Aldo said. "I'm going inside the ring to beat this guy and if it happens again, good. The same thing happened with (Anderson Silva and Chael Sonnen fighting twice). If it happens again, for me, it's good."