Fifa says it "regrets" the scenes leading to the suspension of Brazil and Argentina's World Cup qualifier which stopped "millions of fans" from enjoying the game.
Sunday's match was abandoned just after kick off after Brazilian health officials objected to the participation of three Argentine players they say broke quarantine rules. Fifa said it had received the first reports from match officials, which will now be analysed by "the competent disciplinary bodies". No date for the rearranged fixture has been set.
Brazil's health authorities had said four England-based players for Argentina had to quarantine. Although it did not name the four, the players with English Premier League clubs are Emiliano Buendia and Emiliano Martinez of Aston Villa, and Giovani lo Celso and Cristian Romero of Tottenham. Martinez, Lo Celso and Romero all started the game in Sao Paulo.
The Argentine Football Association said on Monday that all four players were returning to their clubs, but because of UK quarantine rules, they will miss their Premier League games this weekend.
"Fifa regrets the scenes preceding the suspension of the match between Brazil and Argentina which prevented millions of fans from enjoying a match between two of the most important football nations in the world," world football's governing body said in a statement.
"The first match official reports have been sent to Fifa. This information will be analysed by the competent disciplinary bodies and a decision will be taken in due course." On Monday, Brazil's federal police said they had opened a formal inquiry into the actions of the Argentine players accused of breaching the country's quarantine rules.
Brazil's quarantine rules state that visitors who have been in the UK in the 14 days before entering the country must quarantine for 14 days on arrival. "We can confirm an investigation has begun into the possible crime of supplying false information," said a spokesperson. "Yesterday, the players were notified they must leave the country, which is the regular procedure, and statements from them were taken."
Speaking in a video address to the European Club Association's general assembly, Fifa president Gianni Infantino urged Europe to show flexibility in its thinking in order to help South America resolve its qualification backlog. It comes after the UK Government ignored Infantino's request to grant quarantine exemptions to footballers so they could fulfil their international commitments.
"We have a difficult situation in the UK. Players have to go back to play for their countries," he said. "In March, the South American players stayed with their clubs but now they have to play the qualifiers for their national teams.
That is why I called for solidarity. "We have to give hope to countries who only see their best players when they play for their national teams. We have to protect the World Cup. "September has not been ideal, let's find the right compromise for October and November and next year."