Aston Villa striker John Carew is bracing himself for several weeks on the sidelines with the knee ligament injury suffered against Everton.The Norway international limped out of the action early in the second half on Sunday after scoring the opening goal - his first of the campaign - in Villa's 2-0 Premier League victory. Carew underwent a scan today and Villa will make no official statement until the full extent of the results are known within the next 24 hours. But it is understood Villa manager Martin O'Neill's initial fears that Carew could be out of action for a considerable period will be realised. It is a big blow as the power and strength of Carew as well as his ability to hold up the ball offers an alternative to the pace and trickery of Gabriel Agbonlahor and Ashley Young. The player signed from Lyon in January in a swap deal with Milan Baros was just starting to show signs of his best form after an early-season groin problem. A Villa spokesman said: 'We will not know how long John Carew will be out of action until we know the full extent of the scan on on his knee on Tuesday.' O'Neill said: 'This is a blow to John because the goal he had scored had given him a lot of confidence and he was looking excellent in the 10-15 minute period before the injury. 'Whatever they might say about contributing on other areas being important, all strikers gain confidence from scoring goals. This is not what John or we wanted.' Carew's injury means Agbonlahor is likely to revert to a central striking role on a more permanent basis after being used at times in the right flank role by O'Neill.