Will Des Hasler abandon his favoured underdog status when his star-studded Bulldogs side begins their 2015 campaign?

As most of you know, Bulldogs coach Des Hasler used to be a school teacher. So it shouldn't surprise you then when he predicts up to 21 penalties will be blown per match this week. 

It shouldn't surprise you, because he's done the maths. And according to Hasler's calculations, the maths says rule changes equate to an average of almost two dozen penalties per match, per opening round of an NRL season. 

"I'm expecting the rule change – oh sorry, the interpretation – to have an impact," Hasler told reporters on Wednesday. 

"That could be anywhere between maybe 18 to 21 penalties average I think, for the first round. That's what happened in the past anyway when rule changes have come in. So we'll see."

The only change heading into the 2015 season is an interpretation in the ruck whereby referees will instruct defenders to release ball-carriers immediately in a tackle instead of peeling off one by one.

The goal is to limit wrestling and promote attacking football. The result, Hasler believes, will lead to a bigger penalty count on the first weekend of the season. 

Asked where most of the 18-21 penalties would come from, he replied: "Probably the ruck. Probably the so-called wrestle.

"It's gone from massive peel to tackle, release, no peel. So we'll see. Hopefully Tony [Archer, referees boss] and his counterparts are also reasonable and pragmatic about it. 

"But if you go with past trends, penalty counts are pretty high early in the season. Tony might be busy on Monday morning. We'll see.

"Until you get to real time, and the real game sense, you won't really know. But if it's any indication, they're going to be pretty harsh on it. That's the indication you get," he said. 

"And if they're going to do that, there's certainly an area – and it's in interpretations – so it kind of makes it grey, hence my earlier statement that I think there'll be a lot of penalties. But we'll see."

Meanwhile, prop Sam Kasiano looks set for a big season after cutting an imposing – and rather slimmer – figure at training. Hasler predictably avoided drumming up any unnecessary attention on the – according to the Bulldogs website – 122 kilogram front-rower.

Asked whether he was pleased to see the lumbering prop in peak fitness, Hasler responded: "He's just been steady... he's just a big human.

"He had an unfortunate injury last year. At the time he was playing really good footy. Sam just wants to play. When he is playing, he's a handful. We're relying on him in those parts of the game where he's most lethal."

Teammate Aidan Tolman, who is likely spend time at lock after the inclusion of three props on the bench for Sunday's clash against the Panthers, said it was important Kasiano regained the confidence he displayed in his 2012 season.

"He's a talented athlete. He's very skilful and his size is right up there with the best of them in the game when he's playing well. So that's what he needs to do, he needs to get that confidence back that he had last year," he said. 

"He was playing with injuries last year and I think the season before that as well. He needs to get back playing consistent footy. And when he is, there's not that many people that can stop him."