Yannick Bolasie will be requiring surgery after sustaining a knee injury, Everton has described as serious.
The winger was brought off in the 68th minute of the 1-1 draw against Manchester United and underwent scans for the problem.
The club have since announced that the 27-year-old has sustained cruciate ligament damage and will be operated on this week.
“Yannick Bolasie will undergo surgery after sustaining a serious knee ligament injury against Manchester United on Sunday,” an Everton statement said.
“Scans have now confirmed anterior cruciate ligament damage to the right knee. Bolasie will undergo surgery in the next few days.”
Initial reports have suggested that he could be out for the remainder of the season.