Borussia Dortmund star Erling Haaland has suffered a torn hamstring and will be out until January, the club have confirmed.
Dortmund announced the injury news when revealing their line-up for Wednesday's Champions League clash against Lazio.
Speaking to Sky Germany prior to the match, head coach Lucien Favre admitted that he may have made a mistake by not giving Haaland more rest.
“Haaland will not be able to play until January," Favre said. "He may have played too much.
"At first we thought it wouldn't be that bad," Favre added on the injury Haaland suffered in training. "But he can't play now."
The injury is a major blow to Dortmund, with the 20-year-old having established himself as one of Europe's best strikers since joining from Red Bull Salzburg in January.
Haaland scored 15 goals in just 18 appearances for Dortmund last season and has started the current season even better, with 17 strikes in 14 games across all competitions.
Dortmund have a busy fixture list for December, with seven games remaining in the month. Haaland is now set to miss all of those matches, which will take place across the Bundesliga, Champions League and DFB-Pokal.
With Haaland out, Dortmund could rely more heavily on 16-year-old sensation Youssoufa Moukoko, who recently became the youngest player in Bundesliga history.
"I think he’s the biggest talent in the world right now. 16 years and one day, that’s quite amazing. He has a big career ahead of him," Haaland told ESPN. Asked about his own talent in comparison, he added: “I’m over 20 years, so I’m getting old now, so that’s how it is."
Haaland is closing in on current Man Utd head coach Ole Gunnar Solskjaer's record for goals by a Norwegian in the Champions League.
Solskjaer, who coached Haaland earlier in his career at Molde, has 20 career Champions League goals and spoke earlier in the week about the forward, who has already scored 16 in the competition.
"He’ll beat it and very quickly, that’s for sure," Solskjaer said. "The boy has had a great start to his career.
"It was really good to work with him, to see the potential in him, and some part of me feels proud of having a little bit of an input in such a rise. I’m sure Erling will score loads in the Champions League."