Everton midfielder James McCarthy will be out for three weeks after undergoing groin surgery, confirmed manager Ronald Koeman.
Koeman will be without McCarthy, who has not played since Everton's EFL Cup win against Yeovil on August 23, as he was forced off with a groin strain in the 4-0 victory.
Live Monday Night Football
"James McCarthy has had groin surgery and will be out for three weeks," Koeman told reporters at his pre-match press conference ahead of Monday Night Football against Sunderland, in a contest which sees David Moyes return to his former club.
The 25-year-old joined up with the Republic of Ireland squad in preparation for their opening World Cup qualifier in Serbia which resulted in a 2-2 draw.
But after missing the warm-up friendly against Oman on Wednesday the week before, McCarthy was released by Ireland to return to Finch Farm for continued treatment.
Now that McCarthy has had surgery, he is expected to miss Premier League matches against Sunderland, Middlesbrough, Bournemouth and Crystal Palace as well as an EFL Cup third-round tie against Norwich City on September 20.