The other is an up-and-coming centre who has overcome back-to-back knee injuries to become a defensive menace.

Raiders rookies, prop Shannon Boyd and centre Matt Allwood, will be thrust into the NRL spotlight for Saturday night's season opener against the North Queensland Cowboys in Townsville.

Boyd can hold his own physically against James Tamou and Matt Scott, weighing in at 122 kilograms to be the heaviest player on the field.

The 21-year-old Boyd has had that advantage over his rivals since he was a hulking 16-year-old tipping the scales at 110 kilograms and playing in the under-18 competition in Cowra in western NSW.

Under-18s coach Steve Sutton suggested Boyd attend a trial for Canberra's SG Ball team.

''He's always been a big unit; he was a bit sloppy back then and had a lot of puppy fat on him,'' Sutton said.

''Given his size, it was just a matter of if he had the desire to play in the NRL and whether he would become the finished product.

''He's probably more comfortable chasing pigs around in the bush than he is on the football field.''

Boyd's father, Peter, said the arrival of coach Ricky Stuart had given his son more motivation to challenge for a first-grade spot.

''Ricky's gone in at the start of the season and has said, 'I don't care if you've played 300 games of first-grade or none. Whoever is the best player, I'll pick','' Peter said.

''That's what pricked Shannon's ears up and he thought, 'I'm going to give this a really good crack'.''

Both Boyd and Allwood are outside of the club's top-25 NRL squad.

Allwood has come from the clouds to grab the right centre spot vacated by controversial NSW Origin star Blake Ferguson.

Recruited from Farrer Agricultural High School - the same school that produced Raiders captain Alan Tongue and prop Tom Learoyd-Lahrs - Allwood stood out in the club's NYC team before spending 12 months on the sideline with consecutive knee injuries.

He returned last year to become one of the most consistent performers in the NSW Cup for Canberra's feeder club Mounties.

Raiders recruitment manager David Hamilton said Allwood possessed a steely defensive game to go with the ability to break the line in attack.

''He's jumped out of the ground in the past 12 months since he's getting the confidence back in his knee,'' he said. ''Playing against men in the NSW Cup really helped him last year.''