Not only is the veteran lock the biggest and most experienced player in Canada's squad, he's also the most brutal. That will help against a Tongan team renowned for bringing physicality to every exchange.
But while Cudmore's aggression has at times earned him the ire of officials, with a handful of red cards and weeks worth of suspensions for his infractions while playing in the French Top 14 for Clermont Auvergne, he's bidding to play it smart for Canada.
"If I can add in any way with my style of play to help the team, I'm going to do that," the 33-year-old Cudmore said of his uncompromising style. "You'll find (other) guys who have that same kind of attitude. Added with a bit of intelligence and a bit of maybe holding myself back a little bit and trying to stay in the team game, it's going to help us out a lot more come tomorrow night."
Cudmore has only this year rejoined the national team for the first time since 2007. He has played in three tests — all wins, against Russia and twice against the United States — coming into his third World Cup.
He is the only remaining starter from the last Canada team to beat Tonga at the World Cup, in Australia in 2003, and knows what to expect against the Pacific Islanders. Tonga played the opening match of the tournament against host New Zealand, rallying to contain the All Blacks in the second half of a 41-10 defeat.
The Canadians were watching that match on TV and picked up some ideas about where to attack Tonga six days later.
Canada captain Pat Riordan said having the 1.98-meter (6-foot-5), 116-kilogram (256 pounds) Cudmore back with the national squad was a good influence on the less experienced group of mostly semiprofessional players.
"We certainly appreciate his physical presence and his work in the set-piece," Riordan said. "That's not to discredit the other guys. But Jamie brings a level of experience.
"His preparation off the field is key to the guys. That's maybe one of the differences of doing it day in, day out for your pay check. How you physically and mentally prepare for the games. That's been a good learning tool for the guys."
They're going to have to learn quickly, because the turnaround to Canada's second match is only four days. The Canadians play France on Sunday, so they're desperate to open with a victory.
Canada has beaten Tonga in both their previous World Cup meetings, dating right back to their first matches at the inaugural tournament here in New Zealand in 1987.
Canada moved on from there to make the quarterfinals in 1991, but hasn't kept pace with the other tier two countries since then and is now the lowest-ranked team in a group also containing No. 1 New Zealand, two-time World Cup finalist France and Japan.
While Cudmore is one of the few in the Canadian squad who works abroad — he has been at Clermont since 2005 after other stints in Britain and France — the Tongan team comprises players contracted to a wide variety of European and New Zealand clubs.
Coach Kieran Crowley, who was part of the New Zealand squad which won the 1987 World Cup, is aware of the difficult assignments his team has in Pool A. But he's still targeting a third-place finish in the group stage — which means wins at least against Tonga and Japan — so that Canada can qualify automatically for the 2015 World Cup.
Which is why Crowley is happy to have Cudmore back in the national setup for the first time since he took the Canadian job in 2008.
"Jamie brings that physicality of the French style of game to the team and provides a bit of backbone to our team with that," Crowley said. "Held in the mantra that he is throughout Canada due his long-serving time and over in France, he certainly brings that aura around him. He's been really good with the guys to go with that.
"You need it. You've got to have the physicality against these teams."