Craig Bellamy fully expects Cooper Cronk to share Melbourne Storm's secrets with the Sydney Roosters but says the halfback won't know everything his former NRL club is up to.

After 14 seasons with the reigning premiers, the veteran joined the Roosters on a two-year deal after moving to Sydney to be with his fiancee.

He went with Bellamy's blessings, although the coach would have preferred he retired rather than lined up against the Storm.

"I don't particularly like him playing with another team but it's his decision and what's best for him," Bellamy said on Tuesday at the announcement his club would host Leeds in the World Club Challenge in February.

"I would have preferred that he didn't but he'll always have my support in whatever he wants to do."

After playing his entire NRL career in Melbourne, Cronk knows the club inside out and Bellamy believes the Roosters would benefit from that.

But he said the Storm would be making changes to accommodate his absence and the departures of Jordan McLean (Cowboys) and Tohu Harris (Warriors) and would be tweaking their playing style.

"He can share a whole heap if he wants and I'm sure he will," Bellamy said.

"We won't be playing the same style next year, mainly because we haven't got him.

"We try to tailor the way we play to the strengths of our players so we'll have different players next year so we'll be changing a few things."

Storm newcomers including former Raiders winger Sandor Earl, who is returning from a four-year doping ban, have commenced training.

Bellamy said he'd been impressed by Earl's fitness and attitude.

"He's in really good shape and we have to get him in good footy shape now," Bellamy said.

"He's had a great attitude and he's impressed all of our staff with his willingness to work and also to ask questions and try to find the best way to be doing things so we're really happy with him."