Cronulla captain Paul Gallen admits he has no idea what lies in store for the NRL club as the Australian Sports Anti-Doping Authority (ASADA) prepare to step up their investigation into the use of banned substances.

The Sharks showed no signs of being a club in crisis as they brushed aside the Warriors 28-4 on Sunday at a sun-baked Sharks Stadium.

But with ASADA set to send out letters to players they want to interview as part of their investigation this week, Gallen knows there could be more drama to come for the club.

"We're just preparing as best we can," Gallen said.

"It's a day to day thing to be honest.

"We get to training, do our job and go home. That's all we're doing.

"The easiest part of our week is playing footy. We've got a fair side here, we've got some good players so when we do get out on the field it's not hard to just do your job."

Veteran utility John Morris, who like Gallen was at the club during the 2011 season which is being probed, admitted the constant speculation had taken its toll on the families of the players.

"It's been difficult for them," Morris said.

"The media coverage has made it tough as they see all the updates and reports and get upset by the stories.

"But the support they have provided for us has been great and hopefully we get a good outcome and get back to enjoying playing footy."

The 32-year-old said he has no idea if he will be one of the players interviewed by ASADA and said until he hears anything, it has to be a case of business as usual.

"It's been really tough as it's something none of us have been through before," he said.

"The players are doing their best and doing what it is they have to do.

"We are sort of getting used to the process now ... it's been over a month where you see all the TV cameras as you rock up to training.

"Everyone thinks the place is falling apart, but when you see the energy around in the sheds after a big win it shows the couture is good."

Also on Sunday, South Sydney and Penrith played out a high-scoring encounter at Centrebet Stadium with the Rabbitohs running out 44-32 winners.

Nathan Merritt's second hat-trick in three games helped Souths record a third successive win and maintain their fine start to the season.

Greg Inglis was in brilliant form for Michael Maguire's side, who will take on Canterbury on Good Friday in what should be a mouth-watering clash at ANZ Stadium.

On Saturday there were wins for Gold Coast over Manly and Sydney Roosters over Brisbane.