Arsenal striker Gabriel Jesus had undergone knee surgery after being injured while away on World Cup duty in Qatar with Brazil.
The 25-year-old sustained the injury in Brazil’s defeat by Cameroon in their final World Cup group game and missed the South American's 4-1 demolition of South Korea in the last 16.
And Premier League leaders Arsenal confirmed on Tuesday that Jesus had already had an operation but gave no information with regards to how long the former Manchester City attacker would be out.
“Gabriel Jesus has successfully undergone surgery to his right knee after suffering an injury during the Brazil v Cameroon World Cup group stage match on Friday,” said the Gunners in a statement.
“Gabby will now begin his rehabilitation programme.
“Everyone at the club is supporting Gabby and will be working hard to get him back on the pitch as soon as possible.”
Jesus made a flying start to his career at the North London club, scoring five goals in his first nine appearances but failed to find the target in his last 11 games for Mikel Arteta's side.
He made two late substitute appearances for Brazil in Qatar and on his first start played 64 minutes before injury struck.
Arsenal are currently five points clear of Manchester City at the top of the table and return to Premier League action on December 26 when they are at home to London rivals West Ham United.
Brazil, meanwhile, take on Croatia in the World Cup quarter-finals on Friday.