Liverpool and Senegal forward Sadio Mane could be out for up to six weeks with a hamstring injury picked up on international duty with Senegal.
Mane, 25, was substituted in the 89th minute of a 2-0 World Cup qualifying win over Cape Verde on Saturday.
He is set to miss Premier League games against Manchester United and Tottenham and both Champions League group fixtures against Maribor.
Mane has scored three goals in five league appearances so far this season.
Senegal, who are top of their World Cup qualifying group, face two crucial games against South Africa on 10 and 14 November, which Mane is also likely to miss.
He was suspended for three games earlier this season after being sent off in the 5-0 defeat at Manchester City, while he also missed the end of last term with a knee injury.
Liverpool won just once in seven matches in all competitions while Mane was at the African Nations Cup in January. They average 2.2 Premier League goals with Mane in the team, compared to 1.6 goals in his absence.
Mané, who scored 13 Premier League goals last season despite missing the whole of January because of the Africa Cup of Nations and the final six weeks of the campaign with a knee injury, has three in four league matches. The injury to Liverpool’s most influential player has come at a particularly bad time with Adam Lallana still struggling to regain fitness after a thigh injury.
Lallana has been sent to the Aspetar sports clinic in Qatar as he continues his rehabilitation and is likely to return in mid-November, along with Mané who will miss the two Champions League games against Maribor and trips to Tottenham and West Ham, as well the visit of Huddersfield Town.
Liverpool will still hope to have Mané in contention for their key European date in Sevilla on 21 November before they host Chelsea four days later in the Premier League.