James Roby, who missed last year's Four Nations tournament due to injury, has been identified as the dangerman for St Helens as Souths aim to win the World Club Challenge for the first time in the club's rich 107-year history.

Rabbitohs and England prop Thomas Burgess, the only member of the squad to have previously played at Langtree Park, believes Roby may have been the difference between the English team beating New Zealand and Australia in the Four Nations tournament.

"He is up there, he is like the English version of Cameron Smith so he is someone we have to keep an eye on," Burgess said. "I think we might have missed him in the England team last year. He is a very good player, he has got a lot of strings to his bow so he is a big threat."

Luke, the New Zealand hooker, said he had played against Roby on a number of occasions at Test level and was aware of the threat he poses for Saints.

"I have been coming up against James Roby for some time, he is a great player and he is definitely up there," Luke said.

"Over the years he has developed into a world-class player so we are going to have to be on our toes. It is not just his scoots from dummy half, it is his general play and picking the right time to pass or run himself."

Luke will be a key player for Souths and has taken on a leadership role with the team this season to fill the void left by Sam Burgess's departure to English rugby union.

The  27-year-old, who missed last season's historic grand final triumph due to suspension, is renowned for his shyness in front of the cameras but has been undergoing media training during the off-season.

"I have only just come up to the leadership group, which is probably why I can speak English a lot better," Luke joked about his new role.

" I was pretty bad in front of cameras and people putting microphones in front of my face but I think I am getting better."

Souths coach Michael Maguire said Luke was now one of his senior players and was thriving on the extra responsibility.

"I gave Issac an opportunity to lead at the Nines and at the Charity Shield too, and he really enjoys that role," Maguire said.

"That is maturity and understanding of the role he plays. He is one hell of a player so he does that on the park and he backs that up with the way he goes about things off the field. Speaking with kids is a great strength of his."

Luke's introduction as captain has been a successful one, the Rabbitohs winning the NRL Nines and retaining the Charity Shield with a 12-12 draw against St George Illawarra under his charge.

However, he will hand over the reins to newly appointed captain Greg Inglis for the World Club Challenge.

Maguire is preparing his team for a tough match and has been telling them about the atmosphere at Langtree Park, which sold out four weeks ago.

Saints prop Mose Masoe has been linked with a return to the NRL next season and will be keen to showcase his talents when he goes up against a Rabbitohs pack led by George Burgess.

St Helens have been hit by the loss of former Penrith halfback Luke Walsh, who is yet to play this season, and skipper Jon Wilkin will partner Travis Burns at the scrum base.

Former St George Illawarra coach Nathan Brown, who steered St Helens to their premiership win, has returned to help out his successor Keiran Cunningham with preparations for the World Club Challenge.

Teams:

St Helens (squad):  Jonny Lomax, Tommy Makinson, Jordan Turner, Josh Jones, Adam Swift, Travis Burns, Mose Masoe, James Roby, Kyle Amor, Atelea Vea, Jon Wilkin, Louie McCarthy-Scarsbrook, Alex Walmsley, Mark Flanagan, Mark Percival, Luke Thompson, Paul Wellens, Joe Greenwood, Andre Savelio.

South Sydney: Greg Inglis; Alex Johnston, Dylan Walker, Bryson Goodwin, Joel Reddy; Luke Keary, Adam Reynolds; George Burgess, Issac Luke, David Tyrrell, Glenn Stewart, John Sutton and Jason Clark. Int: Thomas Burgess, Tim Grant, Chris Grevsmuhl, Ben Lowe, Cameron McInnes, Chris McQueen and Daryl Millard.