The striker has joined the midlands giants from West Ham on a three-year contract for an undisclosed fee, reported to be in the region of £4million.

And O'Neill is backing his latest recruit to shine at Villa despite a season to forget in London last term.

He said: "Marlon has done it before at this level and I am sure he is more than capable of scoring goals for us in the Premiership this time around.

"All right, he did not have the best of seasons last time, but he has come here knowing he will have to fight for his place and I think that speaks volumes about his character.

"I think we've got ourselves a player with plenty of self belief.

"That is not self belief which is bordering on arrogance, but if we can inject Marlon with a little bit more confidence and get the right players around him I believe he can be a real success with our club.

"Two years ago we all thought we had seen the stabilisation of transfer market prices.

"But the new media deal with the Premiership chairmen is having its effect and we are seeing prices start to go up again."

The arrival of Harewood takes O'Neill's spending to an estimated £30million since he arrived at the Villa helm a year ago.

But the former Nottingham Forest and Hammers front man insisted his move back to the midlands brought with it no extra pressure.

Harewood said: "It had looked as if I was going to Wigan and I was very close to sealing a deal there, but I asked for an extra 24 hours to speak to my wife and think things over.

"Then I heard through my agent that West Ham had given Villa permission to speak to me and of course I wanted to keep my options open.

"I phoned Wigan and informed them of the situation and they were very understanding about that.

"But when Martin O'Neill phones you up and tells you he wants to bring you to a club like Villa, and tells you all about his plans for the future, then of course it's a very exciting prospect.

"I had a great time at West Ham and although last season was a struggle down there the club eventually managed to stay in the Premiership."

Harewood admitted he would have some regrets about the way his Upton Park career came to an end.

"Was I disappointed with the way it ended for me at West Ham? Yes and no," he added.

"But my time at West Ham is behind me now and I have to look forward to life with Aston Villa.

"I have come here ready to fight for a place in the team, I am under no illusions there is a shirt waiting for me.

"It is up to me to impress the manager and earn a place in the team.

"But I think I am capable of having a very good season and that Aston Villa are capable of having a very good year as well."