Because nothing at ANZ Stadium could put him through the same challenge he gives himself at training.

A devout Christian, the 22-year-old fasts twice a week and abstains from all food and all drinks, apart from water, for seven hours at the start of the day.

That includes days on, days off and even during the toughest of training sessions.

"It's pretty tough for me with training," To'o told AAP.

"I go from 6am until 1pm with no drink or food. Me and my missus try and go two days a week."

Twice, he tried training without even drinking water.

"But it affected me a little bit too much," To'o said.

"So I drink water but just take that extra hour."

Faith is what links several players at the Panthers, including several of the club's locals.

To'o, Stephen Crichton and Jarome Luai all complete bible studies - key in a year where they are unable to attend service due to the bubble.

"It's tough," To'o said.

"I spoke to my parents about it and they understand. As long as I am staying consistent with everything and praying and fasting.

"Every time I step out in the corner I always pray before and after the game. It just gives me the strength and belief."

The trio also began praying after each match on field, as part of a quartet alongside Spencer Leniu last year.

Now the group has doubled in size, with the likes of Zane Tetevano and Moses Leota joining.

"Me and Bizza (To'o) always try to link up before the games, go and read our bibles," Crichton said.

"I think it takes our mind off the game and centres ourselves to be humble to really prepare well."

To'o and Crichton have been close since their teenage years.

They spotted each other on a train once both dressed in Penrith kit, and struck up a conversation that continues to do this day.

"We just started talking because we were both Samoans," Crichton said.

"We noticed that we went to basically the same church... he's always dancing and singing, he's a happy guy."

They've also had every reason to be happy this year on the run to the decider against Melbourne.

Crichton has been part of the most successful left edge in the competition, and has a chance of a State of Origin debut next month.

To'o, meanwhile, said he would preference NSW over Samoa if given the chance in future years, after laying the foundation as a powerhouse on Penrith's right wing.

"Samoa would always be there, but I wouldn't mind throwing my hand up for Blues," To'o said.

"I have always wanted to play for NSW."

Australian Associated Press