Rising Bulls star Jamie Peacock goes head-to-head with Adrian Morley on Friday aiming to prove he's a worthy candidate to partner the Leeds Rhinos ace in England's back row for the forthcoming World Cup.

After finally deciding to plump for England, instead of Wales or Ireland, on an ancestry qualification the Rhinos giant seems a certainty to line up for John Kear's men against Australia in their tournament opener against favourites Australia at Twickenham on October 28.

But the other second-row spot seems wide open and Peacock is making a case to pip some more seasoned campaigners for the role.

The Bulls coaching staff are reluctant to pick Kear's team for him, but they have no doubt the 22-year-old has the qualities.

"The desire in the boy is phenomenal - he wants to get better," said Bulls' assistant coach Brian Noble.

"He asks questions, works very hard and will continue to get better.

"Five years ago, when he came to the club, he couldn't catch a ball."

Peacock will not have to do battle with another tough Rhinos' competitor Barrie McDermott, who is being rested because of a knee problem. Jamie Mathiou is set to deputise.

Former Odsal winger Graham Mackay is also out with a fractured cheekbone sustained in a high tackle by St Helens' Vila Matautia, who last night received a six-match ban which will rule him out for the rest of the season.

But Mackay's berth will be filled by Kiwi Test centre Richie Blackmore who is back after a two-match ban.