The NRL was rocked on Wednesday when the Rabbitohs confirmed Burgess had been forced to retire due to a chronic shoulder injury.

But the focus now turns to which big-name the club will chase to fill the million-dollar hole left by his departure.

The announcement came just two days before a galaxy of stars enter the final year of their current deals and are allowed to field official offers from rival teams.

Just how much salary cap space Souths will have is yet to be determined, with the NRL investigating the circumstances around Burgess' career-ending injury.

The 30-year-old England international had three more seasons to run on his reported $1million-a-year deal, signed just over 12 months ago.

Brisbane powerhouse David Fifita has already been linked to the club, however it is Frizell who could be at the top of Rabbitohs' wish-list.

The St George Illawarra second-rower has been forced to repeatedly address rumours of his unhappiness in Wollongong over the past year.

Cook knows Frizell well, having gone to school with him on the NSW south coast.

"It's a bit early to be talking about replacing Sam already but the club does, we do have to move on from Sam as well, as much as he's given our club," Cook said.

"Sam's going to stick around as well I'm sure and give us, make a massive impact away from the game as he did on the field."

Frizell was in his first season with St George Illawarra but third year of his career when Cook made his first-grade debut at the Dragons in 2013.

Six years on and the pair are staples in the NSW State of Origin team and the Kangaroos, who face a Tonga invitational team in Auckland on Saturday.

"Talking about Friz personally, obviously he's a great player and I might have to have a good word to him in here (while in camp)," Cook said.

"You'd take him. Any club would take Tyson Frizell.

"If South Sydney end up with him, that'd be great."

Australian Associated Press