Bulldogs back-rower Raymond Faitala-Mariner.

The change in Bulldogs back-rower Raymond Faitala-Mariner's form and demeanour this season has been startling, and he credits the faith shown in him by new coach Dean Pay for unlocking his potential.

When NRL.com first interviewed Faitala-Mariner at Belmore shortly after his arrival from New Zealand in 2016, he was polite but seemed intensely shy and softly spoken. He showed promise on the field in his 30 matches over two seasons under Des Hasler but looked like a player who could offer plenty more.

Faitala-Mariner recently told NRL.com he was nervous when he first heard about the coaching change but received a boost at the start of the pre-season when Pay pulled him aside and told him he wanted him to become an 80-minute starting back-rower.

Addressing journalists at a club media session on Tuesday morning, the Samoan international – these days boasting a huge, unmissable mop of hair – was a radically different person to the shy 22-year-old who first fronted the Sydney media in 2016.

Laughing and joking and flashing a beaming smile, Faitala-Mariner praised Pay for bringing his confidence to the fore, simplifying his game, encouraging him to run hard and tackle hard, and clearing his head of outside noise.

"It's been a big step from last year, playing 30 minutes each game, going from 30 minutes to 80 minutes," Faitala-Mariner said.

"I had a big off-season, the coaches did a lot of work on me in the off-season and as a result I lost a bit of weight [from 110 kilos down to 105]."

He admitted he left that meeting with Pay on the first day of training last year feeling flattered the new coach wanted him to play a major role in the new-look side.

Faitala-Mariner refused to blame Hasler for his slow start in blue and white ("Des is a great coach", the back-rower insisted) but said Pay's approach suited him to a tee.

"The difference is that Deano has shown more trust in me which has given me a bit of confidence," he said.

"It's given me confidence as a player to do what I can do on the field. Deano's really simplified my game. All he wants from me is to run hard and tackle hard. I don't have a lot going upstairs in my head!

"Every week he comes up to me and says 'just run hard and tackle hard, that's all I need you to do'. So I say 'oh cheers thanks!'."

Senior Bulldogs forward Greg Eastwood said Faitala-Mariner seemed shy when he arrived but benefitted from some of the other Polynesian players taking him under their wing.

"When he first moved over he was a pretty shy guy. The Polynesian guys got around him and made him feel welcome and now he gives it to everybody!" Eastwood laughed.

"He's definitely come out of his shell which is good. He's sort of one of our leaders now in the team and he's playing great footy."