Sunderland keeper Simon Mignolet is facing around two months on the sidelines after suffering a severe fracture of his nose and eye socket in the 2-2 draw with Aston Villa at the end of October. Mignolet sustained the injuries after a collision with Villa striker Emile Heskey.
But the Belgian international is currently unable to maintain his fitness levels as he is still troubled by the after-effects of the clash.
Mignolet said: "I can't do anything. I can't keep up my fitness and it is frustrating.
"I can't even ride a bike, as I get headaches and nosebleeds.
"I did not take offence at Heskey but goalkeepers need protecting."