Premier League clubs last week unanimously decided not to release players for international duty that required travel to countries on the UK's COVID-19 red list.
People travelling to red-list countries are required to quarantine for 10 days after returning, and Cavani would have missed the league game against Newcastle United on Sept. 11 and the Champions League clash against Young Boys three days later.
There is also a row brewing with Premier League club Aston Villa and Argentina over the international break regarding the selection of Emiliano Martinez and Emiliano Buendia. Brazil are without nine Premier League players include Liverpool trio Alisson, Fabinho and Roberto Firmino.
Meanwhile, Sevilla and LaLiga have requested that the Spanish Football Federation (RFEF) postpone the club's game against Barcelona scheduled for Sept. 11 after Court of Arbitration for Sport rejected the league's move to stop the CONMEBOL World Cup qualifying window being extended.
The two-day extension was granted by FIFA in order to help national teams get in fixtures that were postponed in March due to the COVID-19 pandemic.
The international fixture window in South America will now end on Sept. 10 and many teams have players scheduled to take part in domestic games 24 hours later, including the Sevilla versus Barca clash.
"The RFEF's Competition Committee will meet this week to assess the request. This comes as a result of the Court of Arbitration for Sport's denial to modify the South-American FIFA calendar," Sevilla said in a statement.
The same issue is set to arise in October, with the CONMEBOL window extended again to accommodate extra fixtures.