Wilkinson's work rate has impressed Ashton

The 27-year-old fly-half is fit again after 12 weeks out with a kidney injury and may be on the bench for Newcastle at Leicester on Saturday.

Ashton said: "Jonny is like Tiger Woods. He has got talent, but he works harder than anybody else.

"He has been staggering in training this week, and I hope he will be back in the team as soon as possible."

A series of injuries have meant Wilkinson has not played for England since landing the match-winning drop goal in the 2003 World Cup final.

He has been out for 12 weeks because of a lacerated kidney, but Ashton expects him to be firing on all cylinders soon.

"If Jonny is back and has played a couple of games, it will be about form.

"Recent history shows that when he comes back from injury, he plays better than he was in the game before he got injured. It is almost unbelievable.

"He is a lot more mature now, and I think his understanding of the game has developed during all of his time out injured.

"He brings a wealth of experience, and if you match that with his skill set, you have a world-class player on your hands."

Newcastle rugby director John Fletcher will decide on Friday whether Wilkinson is ready to face the Tigers at Welford Road.

"In terms of Jonny's injury and his fitness, there is not a problem," said Fletcher. "It is just a case of whether he has done enough collision and contact work to be thrown into a game.

"We will give him a bit more contact work before the weekend, and if he comes through, then the chances are he will be on the bench and will come on at some point."