Moses Suli has shed 12 kilos for the second time in 12 months after stern words from Des Hasler and a summer of hard slog on the training paddock.

Suli happily tipped the scales at 112kg - his ideal playing weight - this week thanks to three months of personal "floggings" from trainer Don Singe on top of Manly's gruelling off-season workload.

This time last year Suli landed at Brookvale – his third club in a month – overweight and clinging to a bottom-dollar train and trial deal.

By May he had dropped a dozen kilos of excess baggage and earned a first-grade start under Trent Barrett, who also signed off on Suli's two-year extension last October.

But when new coach Hasler got hold of him at the start of pre-season, a 125-kilo Suli copped a none-too-subtle tip.

Tellingly, he's copped it sweet, sweating out an extra 60-90 minutes of cardio more than his teammates as he worked his way back into Hasler's good books.

"I came in pretty heavy at the start of pre-season and Des got into me straight away," Suli told NRL.com.

"He told me straight up, lose the weight. Des said a good playing weight for me is around 112 to 110.

"I knew I had to put my head down and get it done, I've managed to do that.

"I've had extra sessions and I just went at it hard. I have my own little program that I have to do, and it's on me to get it done.

"It's paying off so far, Donny Singe is flogging me and I love it. I've got a lot of extra cardio, I've got a certain amount of calories that I have to burn before I finish up.

"Sometimes it's an extra hour, hour and a half sitting on the bike or whatever but I get used to it and it's paying off so I'm happy with it.

"I didn't actually see it coming, I didn't think I was that heavy when I came back to training. I came in and Des ripped me. But right now I think he's happy and if I can lose a little more it'd be good, just make things easier for me when I'm getting around the field."

Suli still lives at home with his family in Sydney's south west and commutes at least three hours a day to Manly training on the Northern Beaches.

But the Tongan international has moved on from the 2018 pre-season that threatened to end his NRL career.

Once signed to a mammoth $1.3 million Wests Tigers deal before he'd played first grade, only to be cut loose for, among other things, sleeping in his car while his teammates trained, Suli uncomfortably confronted his rugby league mortality.

Trbojevic brothers enjoying Hasler's coaching methods

Reporting for pre-season training 12kg overweight spells out plainly just how much work is still needed for the 20-year-old to progress.

But not for nothing, even when faced with being one of the game's "could've, should've, would've beens", Suli couldn't see himself with anything but a Steeden in hand.

"I didn't look past footy," Suli said.

"I thought everything was finished though. After the Dogs I had a week off to think about what I wanted to do.

"At the end of it I told my manager 'I want to play footy'. That's all I've ever thought about. Manase [Fainu] came and asked Baz if I could come over and he gave me that shot and I had a month's train and trial.

"I'm happy I'm still here and I'm trying to keep doing things the best I can.

"I don't like thinking back on my past much. If I did, I just wish I could change things. I've lost a lot of things, a lot of chances.

"But I'm still here and I still have this chance. So I look forward and want to do things better".