Eliaquim Mangala is unlikely to feature for Everton again this season after undergoing knee surgery, says Sam Allardyce.
The France international, who is on loan from Manchester City, had an operation earlier this week after suffering an injury on his Everton debut as they beat Crystal Palace 3-1 last month.
Allardyce revealed the 27-year-old will remain with Everton for his rehabilitation at the request of his parent club.
"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," said Allardyce.
"We assessed the scans and we've seen there is a little bit more damage than expected."
Mangala joined Everton in the final stages of Deadline Day in search of improved first-team opportunities, following City's purchase of Aymeric Laporte from Athletic Bilbao for a club-record £57m.
Everton travel to Turf Moor on Saturday as they take on Burnley, live on Sky Sports Premier League.