O'Neill believes the Norway international, currently on World Cup qualification duty with his country, has started to add a greater degree of consistency to his game.

In the past Carew has often hit the headlines with a stunning performance, such as his hat-trick against Newcastle last season, but then been virtually anonymous in other games.

But O'Neill still feels the former Lyon player can take his game to another level if he had that extra self belief in what he is capable of achieving.

O'Neill said: "I've often said this about John, that on his day he can be unplayable. We have seen it on a number of occasions here over the past season and a half for Villa.

"He has at times been awesome and caused massive problems for opposition defenders. But I still think that John hasn't got an utter belief in himself. I think he's more talent than he thinks he has got himself. That's my view. It has always been my view."