Warriors interim coach Todd Payten believes the NRL must "be careful" ahead of rule experiments in round 20 that could further speed up the game.
New rules will be trialled a week out from the finals in two fixtures which won't have any bearing on top-eight positions - Thursday's Broncos-Cowboys derby and Sunday's Warriors-Sea Eagles clash.
The adaptions will result in the six-again penalty rule being used for 10-metre infringements, handovers replacing scrums to restart play after the ball is kicked into touch, nominated forwards exclusively packing into scrums and the NRL Bunker reviewing tries that have been awarded by the on-field referee before a conversion attempt.
Brisbane caretaker coach Peter Gentle admitted his team had felt "a fair bit of frustration" about the rules being announced on a whim when they are fighting to avoid the wooden spoon.
Payten, meanwhile, has some concerns over play becoming too fast. A spate of injuries in 2020 could be linked to fatigue being a bigger factor after the introduction of the six-again rule.
"Parts of me do [have worries], absolutely," Payten said.
"I think the product at the moment is going pretty well ... I think we've got 12 extra minutes of play per game on average since they brought the new [six-again] rules in.
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"You've seen the effect it's had on teams with injuries. The fact that we haven't had a bye, it all contributes.
"Definitely speeding it up – do we need to speed it up any more? I'm not too sure. But I think we need to be careful on how we approach that moving forward."
He predicted the pace will increase again with the new rules.
"The one rule I don't think will have any impact is the scrum, the fact that forwards have got to pack in the scrum," he said.
"But the other rules will speed the game up and bring a little bit more fatigue into it, so it makes it more important that you control the ball and don't have to defend too much."
Gentle, although not entirely pleased with the timing, said the rule trial shouldn't have any bearing on the Broncos' performance.
"It is not ideal getting them being dropped on us this late. No-one has had a real chance to practise them at training," Gentle said.
"They [the NRL] might not see this game as important, but we see this game as vitally important for a number of reasons.
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"There has been a fair bit of frustration around that but we spoke about it this morning [Wednesday]. It is what it is.
"We have had to deal with a lot of not ideal situations this year and this is another one. The only criticism is that they came through late. They came through [on Tuesday].
"They are experimental and I understand why they do it, but a bit more notice would have been handy."
He added: "I don’t know how big an impact they are going to have on the game. Obviously the scrum defence is one with the backs being out of the scrum. That is something we had a look at this morning.
"The other ones will be led by the referees, like the 10-metre infringement which will be six-again.
"The forwards now have to find their way to the scrum like the old days and the backs stay out of it. They aren’t drastic changes and there won’t be any excuse if the result doesn’t go right."
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On another note, Payen revealed Warriors captain Roger Tuivasa-Sheck selflessly declined an early return home this week.
The fullback, who hasn't seen his family in almost five months, is sidelined after suffering a hamstring strain last round.
The club initially thought it wasn't feasible to get Tuivasa-Sheck to New Zealand before the team's charter flight home, however they "found out that we could put him on a plane".
"And we floated the subject with him and he was adamant that he wanted to stay," Payten said.
"That sort of typifies the type of leader he is. I said he should think about it for at least 24 hours and he was adamant the next day that he wanted to stay.
"I reckon if the players knew that they would've encouraged him to get on the plane."
