On-loan defender Eliaquim Mangala is set to miss the rest of the season after undergoing knee surgery, Everton manager Sam Allardyce has said.
Mangala, on loan from Manchester City, had to come off before half-time in the 3-1 home win over Crystal Palace, and Allardyce said scans had revealed the damage to be worse than expected.
The France international had surgery earlier this week and will remain with Everton for his rehabilitation at the request of City.
Allardyce told a news conference: "I think it is highly unlikely we will see him again this season.
"Manchester City want us to rehabilitate him so we will do that.
"We assessed the scans and we've seen that there is a little bit more damage than expected."
Allardyce also addressed speculation that he could leave Goodison Park at the end of the season.
"I am here as long as I win football matches, and if you don't win football matches it doesn't matter how long your contract is," he said.
"At the moment we are in a very good position. I am slightly surprised about the situation [speculation about his future], but you can look at the two differences between us -- good at home and not good enough away from home."
He also hit back at criticism of the style of play under his charge, saying it "is only brought up by previous people making out from many years ago we were playing this type of football, which is 10 years ago past."
Information from the Press Association was used in this report.