Oslo - Norway and Aston Villa striker John Carew's back injury will take longer to heal than previously thought, his agent told Norwegian broadcaster NRK on Tuesday.

Carew, who last played on November 22, told Norwegian media last month that he would be sidelined for four to five weeks.

"It is hard to say when John will be back. Maybe in February, maybe in March or later," Per Flod told NRK.

"This is an injury that will take time. It is important that John is completely healed."