Everton say defender Ramiro Funes Mori is likely to miss the rest of the season after suffering a torn meniscus playing for Argentina against Bolivia earlier this week.
The Toffees, who face Liverpool in the 228th Merseyside derby on Saturday, have already lost right-back Seamus Coleman for several months after an horrific double fracture of his leg playing for the Republic of Ireland against Wales.
Coleman's clubmate James McCarthy also aggravated a hamstring injury in the warm-up to that game.
"It has been confirmed that the defender suffered a torn meniscus in Argentina's 2-0 defeat to Bolivia on Tuesday evening," said a statement from Everton.
"He will have a surgical opinion next week but the initial diagnosis suggests the 26-year-old is likely to be out of action for the rest of the campaign."
Off the field, Friday will see the initial stage of Everton's plans for a new stadium go before Liverpool City Council for approval.
The cabinet is being asked to sign off the proposals for the establishment of the funding vehicle which will allow the club to borrow the necessary money, guaranteed by the council, to finance the new £300million-plus ground at Bramley-Moore Dock.
Once the report has been approved Everton can then begin the planning process which would potentially lead to the submission of a formal planning application by the end of the year.
The cabinet report claims a new stadium would bring a forecasted £9million in economic benefits to the city annually and could play a part in their Commonwealth Games bid, either 2022 or 2026.
There will be no financial outlay towards the project by the council but its involvement in supporting the funding model will bring in a £4m-£5m annual security fee.
According to the report Everton "intend to use the stadium move to facilitate a vital legacy project at Goodison Park, delivering health, education, affordable housing and public spaces for the local community".