Bryn Hargreaves will go into the new season leaner and meaner than ever before as he bids to acclimatise to the rule changes that will turn up the heat on props.

The number of substitutions during matches will be reduced from 12 to ten from next season and, although clubs will still have four players on the replacements bench, coaches will have to make more use of their 17-man squad.

The move is designed to restore some of the old-fashioned virtues of the rugby league forward and could spell the end for front rowers who have been used in short spells to make an impact from the bench.

The ten-interchange policy is already in use in Australia’s National Rugby League and will now become part of international law.

Bulls front rower Hargreaves, poised to feature in today’s Boxing Day friendly at Castleford where the rules will take effect, said: “The rule is in place in Australia so you have to make it a level playing field.

“If we’re going to compete with the Aussies when it matters, then that’s what we need to do – make it the same game over here.

“It changes the way we need to be as front-rowers because your rotation is going to be a bit less, so I’ve been really knuckling down and trying to get a lot fitter this year.”

The former St Helens man, who joined Bradford a year ago, has shed several pounds in a bid to get himself in peak physical condition ahead of the new season.

“I’ve trimmed down a little bit so we’ll just see how it goes at the start of the year,” said Hargreaves.

“Hopefully we’re looking good as a squad and I’m really pleased with the way I’m going in training at the moment. I’m probably the fittest I’ve ever been.”

Despite the departure of long-serving skipper Andy Lynch, Hargreaves reckons the Bulls remain strong in the front row.

Craig Kopczak enhanced his reputation with some excellent performances for Wales during the Gillette Four Nations competition and Nick Scruton is returning to full fitness after an injury-ravaged 2011 campaign.

With Tom Burgess having made significant strides last term, and Manase Manuokafoa being recruited to replace Lynch, Hargreaves sees plenty of reason for cautious optimism.

He said: “We’ve got some big guys up the middle. With Lynchy going, a massive workhorse like him, means a lot of the onus is going to fall on guys like myself to up my work-rate and maybe more minutes depending on how the other lads go.

“But I’m looking forward to the start of the season. It’s looking like a promising front row and one of the more positive aspects is that it’s a really young front row.

“Normally in a front row you get some of the more senior, experienced players but we’re all at a good age and that bodes well.”