Aston Villa will be without Thomas Sorensen for around a month after scans confirmed the goalkeeper needs surgery to cure knee ligament damage.
The Denmark international suffered the injury following a collision with Middlesbrough's Emanuel Pogatetz in last weekend's 1-1 draw at Villa Park.
"The way it looks at the moment is that he will be out for two to three weeks," admitted Villa boss Martin O'Neill.
"Thomas has got a bit of ligament damage and we don't yet know exactly how long he will be out for.
"He's booked in for an arthroscopy on Wednesday to see if there is any damage to the cartilage and if there is, we will do something about it."
In the absence of Sorensen, Villa will turn to former Arsenal and England Under-21 international Stuart Taylor who has already deputised for the Dane this season.