Premier League clubs have received a boost after 47 countries - including Argentina, Mexico and Senegal - were removed from the UK Government's red list.
As of 4am on Monday, fully-vaccinated travellers returning from those nations will no longer have to quarantine in a government-approved hotel for 11 nights.
Only seven countries - Colombia, Dominican Republic, Ecuador, Haiti, Panama, Peru and Venezuela - will remain on the red list.
Players such as Liverpool's Sadio Mane, Aston Villa's Emiliano Martinez, Tottenham pair Cristian Romero and Giovani Lo Celso, and Manchester United's Edinson Cavani may now not have to self-isolate for 10 days on their return to the UK.
But Brazilian players Ederson, Allison, Fabinho, Gabriel Jesus, Raphinha, Emerson Royal, Thiago Silva, Fred and Douglas Luiz, and Colombia's Yerry Mina and Davison Sanchez will still have to quarantine as Colombia host Brazil in a World Cup qualifier on October 10.
The government announced this week that double-jabbed players returning from red-list countries will be able to complete their 10 days at 'bespoke quarantine facilities' and be allowed to leave once a day to train or play.
Despite the boost for Premier League clubs, many South American players may still miss the first weekend of games after the international break on October 16, as a round of World Cup Qualifiers is fixed for October 14.
Meanwhile, footballers affected by red-list quarantine restrictions have signed a letter to UK Prime Minister Boris Johnson urging the government to cut the isolation period from 10 to five days.
Professional Footballers' Association chief executive Maheta Molango pointed out how the restrictions, combined with the regularity of football's international breaks, will lead to players being away from their families for repeated, extended periods of time.
The letter, countersigned by 44 Premier League, EFL and Women's Super League players, said: "During a congested international calendar, this could lead to players being away from their families and loved ones for over 100 days before the end of 2022."
Molango added that separation posed a "significant risk to their physical and mental well-being".
It concluded: "Considering the ongoing contributions made by professional footballers, the restricted nature and controlled environment of both domestic and international teams, and the global visibility of the English leagues, we hope the government can approve a five-day quarantine."