Brazil striker Gabriel Jesus will miss the rest of the World Cup after picking up a knee injury.
Jesus has been a key player for Arsenal in the Premier League with six goals in all competitions this season following his move from Manchester City in the summer.
At the World Cup, he's been a deputy to Tottenham forward Richarlison but in his first start of the tournament against Cameroon on Friday he injured his knee.
Following scans on the issue, Jesus will play no further part in the tournament and faces a month out. Left-back Alex Telles will also play no further part in the World Cup and may require surgery after he suffered a knee injury.
A Brazilian FA statement said: "As announced by the Brazilian FA after the game against Cameroon, players Alex Telles and Gabriel Jesus underwent tests on Saturday morning. Accompanied by the Brazilian National Team doctor, Rodrigo Lasmar, they underwent an MRI on the right knee that confirmed the injuries and the impossibility of recovery in time to participate in the Fifa World Cup Qatar 2022.
"The coordinator of the Brazilian National Team, Juninho Paulista, is in contact with the sports directors of Arsenal and Sevilla to define whether Alex Telles and Gabriel Jesus remain with the squad in Doha to continue the treatment or return to their clubs."
News of Jesus' injury will cause great concern to his club manager Mikel Arteta with Arsenal top of the Premier League by five points. Arsenal's first three league fixtures after the World Cup will see them face West Ham, Brighton and Newcastle before an FA Cup third-round meeting with Oxford.
With the knockout stages beginning on Saturday, Arsenal players Matt Turner, William Saliba, Aaron Ramsdale, Bukayo Saka, Takehiro Tomiyasu, Gabriel Martinelli and Granit Xhaka all remain at the World Cup.
Brazil face South Korea on Monday in Qatar for a place in the quarter-finals and still have doubts over Neymar and full-backs Danilo and Alex Sandro.
"The physical demand is ever increasing, the time is short, it's a cumulative effect of games and sometimes you don't have the ideal recovery time on your hands," coach Tite told a news conference.
"I don't really know what to say other than that, mentally, the Cup is very demanding. It drains you. The intensity of the matches, the preparation - they are components of analysis that we have to delve into deeper, but they are all considerable."