Duff kicked off his own campaign with a bang by scoring a hat-trick in last Saturday's 4-1 win over Hartlepool United.

And Keegan – who will take a much-depleted squad to Doncaster Rovers tomorrow – is looking for more statements of intent from his players at the Keepmoat Stadium (3pm).

Duff has missed the past two pre-seasons because of injury, and Keegan – having seen how hard the winger has worked since returning to training earlier this month – was not surprised by his performance at Victoria Park.

Keegan told the Gazette: "It wasn't unexpected because of the way he's trained, but the fans will probably go home thinking 'he's different'.

"He's very, very fit. He hasn't had a pre-season for three years, so maybe it's not so surprising as he hasn't been able to build a season around any base. He's worked so hard.

"I think James Milner is our strongest, fittest boy here, but he's keeping up with James. He can do that.

"You saw that out there. The two of them were full of running. They're very, very fit boys. Damien e can play left and right. That's why it was so easy, despite the lack of numbers, for me to pick a midfield – I
could keep switching it around."

Keegan will be without a number of players at Doncaster, not least Obafemi Martins and Michael Owen.

Martins has returned home to Nigeria after the tragic death of his mother, while Owen is three weeks behind his team-mates after a suffering bout of mumps.

He also has a number of other slight injury concerns, and will not take any risks given the size of his squad.

However, Keegan is looking for those he sends out – who have been put through a punishing pre-season of double sessions – to stake their claims to play against Manchester United at Old Trafford on August 17.

He added: "It's a chance for the lads to say to me: 'I want to be in that team come the start of the season'.

"It's a new opportunity for everybody. There are two or three at this club who feel they have not had a pre-season for two or three years because of circumstances beyond their control.

"Damien Duff is a prime example of that and he was fantastic at Hartlepool last week.

"For the players it's an exciting time, and for a manager you just stand back and say: 'Show me what you can do'.

"So far, the training has been outstanding. We've got a new fitness coach in, and I think so far it's been very hard, but the lads have really enjoyed it."