Uefa has strongly criticised Fifa's shock decision not to uphold Folarin Balogun's automatic ban at this World Cup, calling it "unprecedented, incomprehensible and unjustifiable".
United States striker Balogun, who was sent off against Bosnia-Herzegovina, should have served a suspension for the last-16 tie against Belgium (Tuesday 01:00 BST).
But Fifa opted not to enforce an immediate sanction on the 25-year-old, meaning the co-hosts' leading goalscorer will be available to play.
Uefa said that intervening to effectively cancel a suspension at a tournament "crossed a red line".
Of the 188 other red cards at the World Cup, only one other player has escaped a suspension.
That was Brazil's Garrincha in 1962, which was before automatic bans were in place and it was shrouded in allegations of political interference., external
The BBC's US media partner CBS News has confirmed that Balogun's reinstatement came after US president Donald Trump called Fifa president Gianni Infantino on Thursday and spoke about the suspension.
On Sunday, President Trump thanked Fifa for "reversing a great injustice".
The Belgian Football Association (RBFA) said in a statement that it is "astonished" Balogun will not be banned.
On Monday, Belgium's foreign minister Maxime Prevot said: "If a phone call is really the reason for this incomprehensible decision, it would be a blatant violation of the most basic rules of football and sport."
Former Fifa president Sepp Blatter, who was replaced by Infantino in 2016 after a corruption scandal, wrote on X that "football must never become a playground for political power".
Uefa said that an automatic suspension of one match "is not a discretionary option" and it is "a principle embedded in regulations".
"When the certainty of rules is no longer guaranteed by its guardians, the integrity of the game is at stake and the credibility of a competition is undermined," Uefa said in a statement.
"Equally, such a decision creates a precedent in the ongoing tournament, where similar situations will now require an equal treatment, to the detriment of the competition.
"We express our disbelief at such an unprecedented, incomprehensible and unjustifiable decision."
Glenn Micallef, the European Union's commissioner for sport, said that decisions on sport "belong to sporting bodies, not politicians".
"Influencing sporting decisions would undermine the autonomy of sport," he posted on X., external "Our focus should instead be on the real governance challenges facing sport, including the weaponisation of sport for political purposes."
Uefa and Fifa have been at loggerheads over a number of decisions in recent months.
After Omar Artan was denied entry to the United States to officiate at the World Cup, Uefa invited the Somali to referee the Super Cup between Paris St-Germain and Aston Villa on 12 August.
