FIFA has stepped in to make banned USA striker Folarin Balogun available for the World Cup last-16 tie with Belgium - a move praised by US President Donald Trump but slammed by Gary Neville.
The Belgian FA has said it is "astonished" by the decision and will be "investigating all potential options".
"To safeguard the legitimate rights of all participating teams and to protect the fundamental principles of fair play in our sport, both at this FIFA World Cup and at future editions of the tournament, the RBFA (Royal Belgian Football Association) is investigating all potential options," it said in a statement.
Balogun, who has scored three times at this World Cup, was sent off after netting the opener in USA's last-32 win over Bosnia-Herzegovina, when he caught Tarik Muharemovic with his studs in a challenge.
Balogun was handed a one-match ban and was set to miss Tuesday's knockout game with Belgium.
However, on Sunday, FIFA announced it had suspended Balogun's ban for a year.
The White House made a call to FIFA to ask Gianni Infantino to review the red card, according to a person familiar with the call who spoke anonymously to The Associated Press.
Trump, who was awarded the first-ever FIFA peace prize by Gianni Infantino last year, wrote on social media: "Thank you to FIFA for doing what was right, and reversing a great injustice!"
Sky Sports News has contacted FIFA for comment.
However, Sky Sports pundit Neville had a very different view on ITV. "It absolutely stinks, let's be really clear," he said.
"But what stinks the most is that there should be a review process in place. I actually didn't think it was a red card but there should be a process that allows it to be overturned.
"But if there's no process for it to be overturned and then somehow FIFA, from nowhere, have decided to basically let a player play and the rules are the same for everybody, I'd be absolutely raging if I was Belgium or any other team in the tournament that's had a player sent off that might think it's harsh.
"Am I surprised? No, not with this lot."
Before Sunday's kick-offs, there had been 12 red cards issued at the World Cup - only Balogun's ban has been suspended.
How Balogun benefited from the same rule as Ronaldo
FIFA's intervention to allow Balogun to play is similar to a move it made last year, which allowed Cristiano Ronaldo to play from the start of this World Cup.
The Portugal captain faced a three-game ban for an elbow on Republic of Ireland's Dara O'Shea during a World Cup qualifier. Ronaldo was set to be banned for the first two games of this World Cup as a result.
However, FIFA suspended the ban for the final two games.
FIFA cited article 27 of its rules in that case and again for Balogun. It allows FIFA to "fully or partially suspend the implementation of a disciplinary measure."
In a statement about Balogun, FIFA said: "The implementation of the match suspension is suspended for a probationary period of one year. If Folarin Balogun commits another infringement of a similar nature and gravity during the probationary period, the suspension shall be revoked and the sanction enforced without prejudice to any additional sanction imposed for the new infringement."
A social media account for The White House reposted Trump's message on X, adding the words: "USA-USA-USA".
