Several Premier League sides will be asked to cope without some of their players at a key period of the 2020-21 season, with news the Africa Cup of Nations has reverted to winter.
Cameroon will host the 33rd edition of the tournament between January 9 and February 6 of 2021.
The tournament had originally been scheduled for June 11 to July 9.
It means - for instance - Premier League leaders Liverpool could be without the likes of Sadio Mané, Mo Salah and Naby Keita.
Cameroon have requested the switch as June and July is usually the time of a long rain season that would likely affect the tournament.
— Fecafoot-Officiel (@FecafootOfficie) January 15, 2020
It's expected the AFCON 2023 in Ivory Coast will revert to a summer tournament.
Another reason potentially behind the move - without doubting Cameroon's sincerity - is that summer of 2021 is when the first enlarged FIFA Club World Cup is due to be played.
The 24-team tournament is provisionally scheduled for June 17 to July 4 of 2021, which would have seen a sizeable overlap between that and the Africa Cup of Nations.
Both tournaments will provide plentiful headaches for major sides in European leagues when it's factored in that a winter World Cup in 2022 is looming into view as well.
As seen below, based on current Premier League squads and players still playing for their national sides, Liverpool will arguably be the hardest hit by the move to a winter Africa Cup of Nations.
Arsenal: Pierre Emerick-Aubameyang (Gabon), Nicolas Pépé (Ivory Coast), Mohamed Elneny (Egypt)
Aston Villa: Ahmed Elmohamady (Egypt), Marvelous Nakamba (Zimbabwe), Trezeguet (Egypt), Jonathan Kodjia (Ivory Coast)
Brighton & Hove Albion: Gaetan Bong (Cameroon), Yves Bissouma (Mali), Leon Balogun (Nigeria)
Chelsea: Baba Rahman (Ghana), Victor Moses (Nigeria)
Crystal Palace: Cheikhou Kouyaté (Senegal), Wilfried Zaha (Ivory Coast), Jeffrey Schlupp (Ghana), Jason Lokilo (DR Congo)
Everton: Alex Iwobi (Nigeria), Jean-Philippe Gbamin (Ivory Coast), Oumar Niasse (Senegal), Beni Baningime (DR Congo), Yannick Bolasie (DR Congo)
Leicester City: Daniel Amartey (Ghana), Wilfred Ndidi (Nigeria), Islam Slimani (Algeria), Fousseni Diabaté (Mali), Rachid Ghezzal (Algeria)
Liverpool: Naby Keita (Guinea), Sadio Mané (Senegal), Mo Salah (Egypt), Taiwo Awoniyi (Nigeria)
Manchester City: Riyad Mahrez (Algeria)
Manchester United: Eric Bailly (Ivory Coast)
Newcastle United: Christian Atsu (Ghana), Achraf Lazaar (Morocco)
Norwich City: none
Sheffield United: none
Southampton: Moussa Djenepo (Mali), Soufiane Boufal (Morocco), Mario Lemina (Gabon)
Tottenham Hotspur: Serge Aurier (Ivory Coast), Victor Wanyama (Kenya)
Watford: Isaac Success (Nigeria), Ismaila Sarr (Senegal), Tom Dele-Bashiru (Nigeria)
West Ham United: Arthur Masuaku (DR Congo)
Wolverhampton Wanderers: Bright Enobakhare (Nigeria), Romain Saïss (Morocco), Phil Ofosu-Ayeh (Ghana),