The Irishman asked for a chance to refresh, given his impending arrival, as well as his heavy workload in recent years. He's fought four times in the past 12 months, including his historic UFC featherweight and lightweight title victories.
A potential role in the blockbuster series isn't the first time McGregor has crossed paths with the Game of Thrones world. The 28-year-old has previously trained with strongman/actor Hafthor Bjornsson, who plays Gregor "The Mountain" Clegane.
Game of Thrones creators David Benioff and D.B Weiss are known UFC fans and appeared on the UFC Unfiltered Podcast back in July, alongside MMA legend Matt Serra and comedian Jim Norton.
The pair spoke of their UFC fandom, in particular their love for the Irishman. "We stayed up with a group of the actors until 6am in the morning watching the McGregor-Aldo fight in Vegas this past December. We talk more about MMA than we do Game of Thrones," the pair explained. "Every day we get home from shooting we'll just sit around drink beer and watch Fight Pass."
The Game of Thrones chiefs also sat cageside at UFC 196, where they saw McGregor fall to rival Nate Diaz in his initial move to the welterweight division.
But despite their disappointment in McGregor's defeat, the night still almost provided some material for the show, notably Nate Diaz's post-fight speech.
"We loved Diaz's line, 'Surprise Mother******'," the duo said. "We were thinking of rewriting that line in the show."
Conveniently, potential Game of Thrones duties would fit well into McGregor's training schedule, with the show filming in both Northern Ireland and Iceland.
Iceland is home to the Mjolnir gym, which McGregor has used as a training base for his pre-fight camp, with the nations snow-capped regions used to shoot scenes the region known as north of the wall.
Belfast is used for several other filming locations, and is obviously closely situated to McGregor's home in Ireland.
Talk of McGregor's first step into the acting game may not be welcome news to the UFC top brass, with fellow MMA star Ronda Rousey also having made moves to end her time in the Octagon, for a fulltime role in Hollywood.
The loss of one, let alone both of their megastars, would be a huge blow to the mixed martial arts organisation's new owners, entertainment conglomerate, WME-IMG, who acquired the company for $4 billion earlier this year.
Gina Carano is another who has had great success in the acting world after hanging up the gloves, while current UFC Middleweight Champion Michael Bisping stars in the upcoming Vin Diesel led film XXX: The Return of Xander Cage.
But none possess the worldwide appeal and reach of the megastar McGregor, who could blaze a trail in the land of Westeros that would leave even Daenerys in the shade.