Earlier, McGregor - who is reportedly nearing a return to the octagon - wrote: "Enjoying the World Cup final in Russian Federation". Earlier in the day, he had posted a photo of himself in a seat at Moscow's Luzhniki Stadium, exclaiming, "A truly fantastic spectacle!"
Mashable has reached out to McGregor's representatives for comment.
After the game, McGregor paid tribute to Putin and called him "one of the greatest leaders of our time".
He was in the crowd - "a dream come true" according to the star.
Notorious was at the Luzhniki Stadium at the same time as rival Khabib Nurmagomedovm, who he fight.
Former UFC featherweight and lightweight title holder Conor McGregor turned 30-years-old today and received a sweet surprise from his significant other Dee Devlin for the special occasion. His next court appearance is set for July 26. But, the football spectacle also had something for the MMA fans too.
After defeating "The Underground King" in New York, Conor McGregor became the first fighter in UFC history to hold two of the promotions belts simultaneously.
McGregor has not fought in the UFC since he beat Eddie Alvarez in November 2016.