Liverpool forward Sadio Mane was substituted less than half an hour into Senegal's World Cup qualifier with Togo on Thursday.
The 29-year-old lasted just 28 minutes before he was replaced by Boulaye Dia, having sat down on the field to indicate that he couldn't continue.
Mane has been back to his electrifying best for Liverpool in recent weeks, showing the kind of form that sees him regarded as one of the finest left forwards in the world. He has six Premier League goals to his name and eight in all competitions - half the amount he achieved throughout the entire 2020/21 campaign, in which he was relatively below-par.
Moreover, his overall performance levels have been vastly improved, with Liverpool looking back to their potent best both at home and on the continental stage. Mane's also been a shining light for Senegal in their World Cup qualifying campaign, registering three goals in five games.
Liverpool will now anxiously await news of Mane's condition, hoping that his decision to come off was perhaps a precautionary move rather than the result of a serious problem.
The fixtures continue to come thick and fast for Liverpool once the international break concludes, with a hectic December schedule seeing Jurgen Klopp's side play nine games in the space of 27 days.
Liverpool are also playing three times before the end of November, with in-form Arsenal the next opponents at Anfield.
The heavyweight duo are due to clash in the evening kick-off on Saturday 20 November before it's back to Champions League action against Porto four days later. The month is rounded off by a third successive home game, this time against Mane's former club Southampton.
Were Mane to be unavailable for any of those games, it would further compound his already scheduled absence in January.
He's due to be on international duty for most of the month as Senegal take part in the Africa Cup of Nations; a competition that will also see Mohamed Salah, who was named PFA Premier League Fans' Player of the Month for October on Thursday, representing Egypt.