Everton says midfielder Gylfi Sigurdsson could be sidelined for several weeks with a knee injury, presenting a concern for Iceland ahead of the World Cup.

Iceland's first-ever World Cup campaign opens on June 16 against Argentina in Russia.

The 28-year-old Sigurdsson was injured in Saturday's Premier League game against Brighton.

Everton says Sigurdsson "could be sidelined for several weeks but it will only be after consulting with the specialist that a definitive timeframe will be known."

Sigurdsson joined Everton in July for a club-record 45 million pounds (then $58 million).