Unless quarantine exemptions are made, players would be forced to miss several domestic matches because of the 10-day isolation period required on return to the United Kingdom.

The Football Association and Premier League are in talks with the Department for Digital, Culture, Media and Sport over a relaxation of UK rules.

Liverpool is refusing to allow Egypt forward Mohamed Salah and Brazil trio Alisson, Fabinho and Roberto Firmino to travel home to represent their countries because both nations are on the UK Government red-list.

The Egyptian Football Association (EFA) revealed that Liverpool had apologised for not allowing Salah to join up with the national team.

"The Egyptian Football Association has received a letter from Liverpool apologising for the inability of its player, Mohamed Salah, to join the national team in its next camp, which includes facing Angola in Cairo and Gabon in Franceville during the first and second rounds of the African continent's qualifiers for the World Cup," the EFA said in correspondence published on its website.

"The English club's letter referred to the precautionary measures applied in England to confront the outbreak of the coronavirus in the world, which puts returnees from some countries in compulsory health isolation for a period of 10 days upon their return to England.

"In the letter, the English club also expressed its hope that the Egyptian federation would understand that it was forced to do so, in the face of the player being subjected to a quarantine for this period and being affected by this physically."

Liverpool have confirmed that they are happy for Salah to play in the away fixture against Gabon because of not having to enter a red-list country.

FIFA recently extended the September and October international windows by two days in South America, to enable countries to catch up on World Cup qualifiers for Qatar 2022 that were postponed because of the coronavirus pandemic.

The world governing body claimed the two-day extension ensured "sufficient rest and preparation time between matches".

It means matches are now scheduled to be played on September 9 and October 14, with players involved being released for 11 days.

Brazil, whose latest squad includes nine Premier League players, are due to play Argentina, Chile and Peru in next month's qualifiers.

All four countries are currently on the UK's red list.

It is expected that nearly 100 English-based players could be affected next month if their clubs refuse to release them.

The Premier League, Football Association, European Club Association and its members are all lobbying for the UK Government to grant an exemption from quarantine rules.

But the Government denied exemptions to British and Irish Lions players returning from South Africa earlier this month.

Other European-based players who could be affected by their clubs' refusal to release them include Paris Saint-Germain stars Lionel Messi and Neymar, who play for Argentina and Brazil respectively.