Everton star Andre Gomes has already gone through ankle surgery after his injury against Tottenham.
Gomes seriously hurt his ankle after a Heung-Min Son tackle led him to awkwardly collide with Serge Aurier.
But the club says he has gone through a procedure and is now recovering in hospital.
Everton said in a statement: "On behalf of Andre, the club would like to thank all Everton supporters and members of the wider football family for the overwhelming messages of support we have received since yesterday's match."
It is likely that Gomes will be absent for at least six months, but it could be up to 12 months before fans get to see the midfielder line up in the Premier League.
For their part, both Son and Aurier were distraught after Gomes suffered the injury, as it was immediately apparent that it was a serious problem.