UEFA president Aleksander Ceferin skipped Sunday's FIFA World Cup final in an apparent protest against FIFA, according to British media reports published Monday.
The move is the latest sign of growing tensions between European football's governing body and FIFA, the global governing body of football.
One major source of friction was FIFA's controversial decision to overturn the suspension of United States forward Folarin Balogun before the Americans' World Cup match against Belgium.
Balogun had been sent off in the previous game, but FIFA reinstated him after U.S. President Donald Trump publicly urged FIFA president Gianni Infantino to "review" the red card.
UEFA was unhappy that Infantino bowed to what it viewed as political pressure from the tournament hosts. It called FIFA's disciplinary committee decision "unprecedented, incomprehensible and unjustifiable" and said it "crossed a red line."
Other sources of tension included FIFA's acquiescence after U.S. authorities refused to allow Somali referee Omar Artan to enter the country. UEFA responded by appointing Artan to officiate the UEFA Super Cup next month.
FIFA was also unable to ensure Iran was treated the same as other teams playing in the United States. Coach Amir Ghalenoei said his team were the "most oppressed" at the World Cup. U.S. Homeland Security Secretary Markwayne Mullin said he "danced a happy dance" when Iran were knocked out.
UEFA has also, so far, refused to adopt some of FIFA's World Cup innovations, including hydration breaks, the "mistaken identity" VAR protocol that led to Breel Embolo's sending-off in Switzerland's quarter-final loss to Argentina, and yellow cards for players who cover their mouths while speaking to an opponent.
Ceferin also criticized the expanded 48-team tournament before it kicked off.
"We have a lot of matches that are completely uninteresting," he was quoted as saying by a newspaper in his native Slovenia.
Ceferin has also been publicly critical of World Cup ticket prices.
UEFA has said it will continue to offer two "fan first" ticket categories at the 2028 European Championship in the United Kingdom and Ireland. It said 40% of tickets will either be priced below 30 pounds ($40) or below 60 pounds. It has also promised not to adopt dynamic pricing.
Ceferin attended the tournament's opening match in Mexico City on June 11.