Liverpool manager Jurgen Klopp's plans for the pending visit of arch-rivals Manchester United have been thrown into turmoil after Sadio Mane was ruled out for up to six weeks.
The Senegal international sustained a hamstring injury against Cape Verde on Saturday and, after being assessed by the club's medical staff on his return to Merseyside, a scan has confirmed their worst fears.
Mane, who was named on the Ballon d'Or shortlist on Monday, is likely to miss nine matches in all competitions, among those games against United, Tottenham and Chelsea plus three Champions League fixtures, two against Slovenian side Maribor plus the trip to Sevilla,
"The winger was substituted 89 minutes into Senegal's 2-0 World Cup qualifying win over the Cape Verde Islands on Saturday," said a Liverpool statement.
"And it has now been confirmed that he picked up an injury during that fixture that could keep him out of action for up to six weeks."
The pacy forward's absence could not have come at a worse time as Klopp looks to get their season back on track after an indifferent September.
Mane, who scored 13 Premier League goals last season despite missing the whole of January due to the African Nations Cup and the final six weeks of the campaign with a knee injury, has three in four league matches so far.
Since his debut in August 2016 Liverpool average 2.2 Premier League goals with Mane in the team, compared to 1.6 goals in his absence.
When he was at the African Nations Cup in January Liverpool won just once in seven matches in all competitions.
The 25-year-old has endured a difficult last six months after a brilliant start to his Anfield career.
He tore the meniscus in a knee during April's Merseyside derby which prematurely ended his season and required surgery.
Having worked hard in pre-season to get back to fitness the forward began the campaign with three goals in his first four appearances before a red card at Manchester City on September 9 resulted in a three-match ban and halted his progress.