Everton defender Ramiro Funes Mori could be out for the remainder of the season after suffering a knee injury while on international duty.
The 26-year-old suffered a torn meniscus while playing for Argentina in Tuesday's 2-0 World Cup qualifying defeat against Bolivia.
Funes Mori was forced off after just 36 minutes of the game in La Paz.
The initial diagnosis suggests his season is at an end but he will have a surgical opinion next week.
Since joining from River Plate in September 2015, Funes Mori has played 63 times for the Toffees, scoring five goals.