But it took Toronto for the two to almost come to blows.
"It got to a boiling point today," UFC president Dana White told The Canadian Press after a raucous news conference Friday in the heart of the Toronto Eaton Centre.
The wick was almost lit during a morning visit to CTV's "Canada AM." According to White, one of the show's producers opted to put McGregor in a seat right behind the couch where Aldo was situated as they waited to go to air.
White threw out a word of warning but it was ignored.
"And Conor slaps Jose Aldo on the back," said White. "We're about to go live and all hell almost broke loose."
There's a reason why White, who has played ringmaster in every city, has dubbed it the "war tour."
Aldo (25-1) and McGregor (17-2) face off for real July 11 in Las Vegas at the MGM Grand Garden Arena. The publicity tour, which started March 20, has taken the fighters to Rio de Janeiro, Las Vegas, Los Angeles, Boston, New York City and Toronto.
Tickets went on sale to the general public Friday but White said all but a few hundred had been snapped up in pre-sales.
The UFC expects a US$7-million gate, second only in North America to the $12.075 million generated by UFC 129 at Toronto's Rogers Centre in April 2011. Millions more will pour in via pay-per-view.
Fans looked down from two levels above Friday, with some taking a nearby escalator up and down again and again to get a better view of the stage. Public support seemed split between the two fighters.
A video promo of the two fighters was shown before their entrance, to the sounds of Lorde's remake of "Everybody Wants To Rule The World."
The two 145-pounders seem to be growing tired of each other on tour.
"I have learned that my opponent does not want me close," said McGregor. "He always wants somebody to intervene. But on July 11, there will be nobody to intervene."
"I didn't really learn anything about him," Aldo said via his translator, in no mood to share.
The champion has been stony-faced while McGregor has poked and prodded, trying to get under his skin. The more Aldo reacts, the more McGregor seems to like it and vice versa.
The 26-year-old McGregor says the 25-minute fight will be decided in the first four minutes. "He cannot take my power, simple as that," said the Irish fighter.
"Four minutes he will be out on his feet and it will be a formality after that to see how long his battle-worn chin can hold up," he added.
Aldo, 28, promises to make McGregor pay.
"I'm ready for anything that he brings. And trust me, on July 11, it will be a surprise. You guys will all like it."
Aldo has won his last 18 fights and has not lost since November 2005. McGregor, ranked third among featherweight contenders. McGregor is on a 13-bout win streak that dates back to November 2010.
White called the Toronto event one of more "low-key" stops on the tour.
The two have criss-crossed North America in separate private jets. They will fly commercial next, in business class, to Europe.
On Sunday, McGregor is slated to take in Ireland's Euro 2106 soccer qualifier against Poland in his native Dublin while the Brazilian champ watches Brazil play Chile in London.
It's back to pushing the fight Monday in London with a final stop Tuesday in Dublin.
Welterweight champion (Ruthless) Robbie Lawler (25-10 with one no contest) and Montreal-based Rory MacDonald (18-2) meet in the co-main event at the MGM Grand Garden Arena.
Lawler and MacDonald, currently sporting a mohawk, took part in the, New York and Toronto stops as well as appearances in Vancouver and Calgary.
The publicity tour is tailor-made for the charismatic McGregor, a former plumber who has yet to meet a microphone or camera he doesn't like. Aldo, whose English is limited, has mostly played the silent partner.
"I love Brazil. And Brazil loves me," McGregor said on a visit to an Irish pub in Rio de Janeiro where, shirtless and wearing sunglasses, he threw darts at a picture of the champion.
He then tore up an Aldo picture, screaming: "Tell him I'm coming."
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