Kewell gave it a crack at Maine Road in Sunday’s outstanding 5-2 FA Cup victory over Manchester City - scoring twice and claiming the man-of-the-match award.

Now boss O’Leary is even threatening to use the Sydney-born youngster up front in league combat. The 21-year-old has had an outstanding season wide on the left or as a floating, attacking midfield player.

That’s been devastating enough as Leeds have stormed to the top of the Premiership and into the last 16 of the cup after Sunday’s impressive win at Maine Road.

But following the £3million signing of left-winger Jason Wilcox, who played his first full game at City since joining from Blackburn last month, O’Leary believes he has the manpower to test out his theory about Kewell’s long-term future.

O’Leary said: "Everyone can see that he’s not a bad player. And I feel that Harry will eventually play up front. "But I just have to get a few players in - and that’s easier said than done.

"People think that I should be able to get them all the time, bring them in out of thin air and put players here there and everywhere. But when I do get the chance to boost the squad I can try new ideas.

"And I do think eventually that up front is where he will end up playing. I demand more goals from him and you saw him score a couple here.

"Eventually he’s got a chance of being a tremendous player and the way he has got to improve is by scoring more goals - and he’ll do that up front.

"In buying Jason Wilcox I always had it in the back of my mind about playing Harry up front. And I thought the cup tie was the ideal day to try it out, give it a go. "You never know, I may do it in the Premiership now. Just wait and see."

Kewell’s exceptional display - he was only the thickness of a post away from a hat-trick - was the key to Leeds’ success. Twice behind early on to a determined, brave City side - currently top of the First Division - Leeds showed their genuine class with a five-star display for the TV cameras.

It certainly impressed City boss Joe Royle, who rates Leeds chances of winning the Premiership. Royle said: "Don’t let David O’Leary kid you, his boys can win the championship. They were terrific, they were behind twice but we were beaten by a better side.

"They are fast, fit and committed and a different level to us. That’s not something I have had to say since I arrived at City, but sometimes you have to hold your hands up and admit it. "It was a good learning curve for us, and it will bring a few people back to mother earth who think we are better than we are."

But Royle refused to be downhearted. He said: "We have played Derby, Southampton and Wimbledon in the last couple of seasons and there hasn’t been much difference between us.

"But Leeds are in a different league altogether. There are about five sides who can win the title and they are among them. The rest are not much different to us.

"What we saw was us having to make up two divisions, not just one. Leeds have a lot of young lads who are maturing and they believe in themselves. They were awesome at times and the coming force.

"They reminded me of a very young Everton side I used to be in who were equally precocious and just as fast, with one notable exception, me." He added: "As for us, we are improving all the time and are a lot better than we were 18 months ago.

"The keeper Nicky Weaver, Shaun Goater and Ian Bishop at 34 were excellent, but we had a few who let us down and I have told them so. In lots of ways it was a good lesson for us."

O’Leary reckons the two sides could be facing each other in league action next term. He said: "I hope they come up this season and we are back here next term taking points off them, and I think they will come up."