Everton have confirmed Victor Anichebe strained knee ligaments during the 0-0 draw at Newcastle United.
Anichebe was hurt by a horror challenge from Kevin Nolan just before half-time which resulted in the Newcastle midfielder being sent off.
The Toffees were initially hopeful that Anichebe had not suffered a serious problem, with the striker having a heavily bruised shin.
However, Everton physio Mick Rathbone has revealed there is some ligament damage and the club are now waiting to learn how long the forward will be out.
"Victor has got very bad bruising on his shin and on the outside of his ankle, but we're not overly concerned about that," Rathbone told the club's official website.
"However, he has had a series of scans and he appears to have strained ligaments on the outside of his right knee.
"He is very sore indeed and we need to take a few days to let the area settle down before we can properly make an accurate clinical evaluation."
But, despite suffering ligament damage, Rathbone is confident that Anichebe has not picked up a serious knee injury.
Rathbone added: "He's got big strong legs and that helps. I think he's just about got away with it.
"He bent his knee, so the strain came on the outside of the knee."