Premier League clubs will not be obliged to let Portuguese or South American stars represent their national teams in the March international break after world governing body FIFA extended a rule over player release.
Clubs are usually bound by FIFA regulations to release players for international duty but an exemption was added in the wake of the coronavirus pandemic which allows clubs to refuse in a number of circumstances, including where there is a mandatory quarantine period of five days or more on return to their club.
That exemption has now been extended until the end of April.
The UK has said anyone returning from a 'red list' country - which includes Portugal, all of South America and parts of southern Africa - will need to quarantine in a hotel for 10 days.
Elite sports stars are not exempt from the rules.
European champions Portugal are due to kick off their qualification campaign for the 2022 World Cup at home to Azerbaijan on 24 March, but may now have to do so without English-based stars such as Bruno Fernandes or Bernardo Silva.
Brazil's squad for their World Cup qualifiers may also be weakened as a result of the new rules. Chelsea's Thiago Silva, Manchester City duo Ederson and Gabriel Jesus along with Everton's Richarlison and Liverpool's Roberto Firmino all started their last qualifier away to Uruguay in November last year.
FIFA said in a statement: "In the context of the challenges that remain in place for both international and domestic football due to the COVID-19 pandemic, the Bureau of the FIFA Council has decided to provide additional flexibility regarding the release of players for national team duty and the registration of players with clubs in competitions that remain disrupted by the pandemic."