Aston Villa keeper Thomas Sorensen is to undergo an exploratory operation to discover the full extent of the knee injury suffered during Saturday's Premiership clash with Middlesbrough.
But the Denmark international is expected to be on the sidelines for two to three weeks after initial scans showed he sustained ligament damage during a second-half collision with Middlesbrough defender Emanuel Pogatetz.
Villa manager Martin O'Neill confirmed: '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.
'The way it looks at the moment, we're looking at two to three weeks but we will have a better idea tomorrow.'
Sorensen's injury will present a rare opportunity of the season for Stuart Taylor and O'Neill has every confidence in the former Arsenal keeper.
He said: 'He's played a couple of games already this season and this is an opportunity for him.
'When you are out of the side, you're just waiting for the chance to come in and impress and it's all about having a bit of competition.'