Forwards are going to need to be more mobile and fitter than ever, while teams are likely to carry an extra hooker or playmaker on the interchange to take advantage of next season's rule changes.
NRL coaches, players and trainers are already adjusting their plans for 2021 after the ARL Commission on Friday announced eight new rules largely intended to create more unpredictability and speed up the game by reducing stoppages and keeping the ball in play longer.
With the six-again call expanded to replace a penalty for offside, defences are likely to be under increased pressure and bigger forwards can expect less game time as coaches look for more players in the mould of Brandon Smith and Cameron McInnes to play in the middle.
The introduction of a handover instead of a scrum when the ball is kicked into touch or a player tackled over the sideline, and to replace a penalty for an incorrect play-the-ball, will also speed up the game and increase fatigue levels.
"I guess it's tougher for us as players but if it speeds the game up and creates more flow in the game … the more the ball's in play the better the footy is to watch," Sydney Roosters second-rower Angus Crichton said on Monday.
Risk or reward: Two-point field goal explained
"I might have to work on a bit more fitness but I think in the long run it all comes out in the wash. If it's better for the viewer I'm all for it."
Canberra recruitment manager Peter Mulholland believes "mobility is going to need to be enhanced" but said it was too soon to determine what impact the rule changes would have on roster decisions.
Crichton expects new rules to create a faster game
"I don’t think we will know for six months," he said. "Had this been the 1970s or the 1980s it would be different but we have been training full-time since 1995 or 1996.
"Players just adapt. Across the field players have become more uniform in size, you’ve now got 95kg hookers and 90kg halfbacks so we are going to have to wait and see what effect it has on your bigger forwards."
Wests Tigers trainer Ron Palmer believes the rule changes will encourage more ad-lib football and a "helter-skelter" style of play that will require greater fitness levels for players to transition between attack and defence.
"I think you have just got to be up-tempo and ready to go at any moment," Palmer told SEN Radio. "We train these fellows really, really hard as it is and they have all got really tough off-seasons but I now think it needs to go to another level.
"As a general overview we have got to be a lot fitter than we have ever been, particularly the bigger fellow around the middle."
St George Illawarra coach Anthony Griffin believes the advantage of a six-again call for offside could be offset by the loss of field position from a kick for touch if a penalty had been awarded.
Why Cleary edged out DCE for Kangaroos halfback
He said it would depend on how willing referees were to restart the tackle count for 10-metre infringements.
"If you get a six-again on your own 30-metre line you are still in your own half and you don’t get the chance to put a 30m or 40m kick down and set up a set on the opposition’s 30m line," Griffin said.
"I think it is a bit of win for both sides of the ball, you can be offside and not lose field position but you obviously lose the tackle count. If you need to be offside on tackle one or two maybe you are prepared to make eight tackles."
NRL ready to adapt if the 2021 RLWC is cancelled
Griffin doubted conceding a handover instead of a scrum would deter playmakers from kicking into touch late in matches to wind down the clock if their team was ahead.
"It probably suits the attacking team that is going into defence because they don’t have to defend a scrum," he said. "If you kick it into the corner and the opposition have got to play the ball 10 metres out from the sideline it is a bit of an advantage for you defensively."
However, he expects more points to be scored from scrums if match officials enforce the new rule requiring players to stay bound until the referee calls "break".
A full penalty will be awarded for infringements, enabling teams to kick for goal, while they will also have the option of repacking the scrum and a second breach would result in a sin-binning.
"That is obviously borne out of teams deliberately giving away penalties in a scrum but you don’t want to be giving away two points or having a player in the bin so that will loosen up the defence around the scrum, particularly on your own line, which is a good thing," Griffin said.
"They won’t have offside defence in front of them now."
New Brisbane coach Kevin Walters believes the rule changes will benefit his side next season as they try to climb the ladder after finishing last for the first time in 2020.
The best steps from the 2020 season
"The more we can keep the ball in play that’s when the more skilful players come into their own," Walters told Sky Sports Radio.
"Guys like Anthony Milford can really show his class. The longer the games goes and the more the ball is in play, his skills really come to the fore.
"We have got to work within the rules and use those rules, I believe, to the Broncos’ advantage. The type of people we have in the team at the moment certainly suit the rule changes and that style of football.
"We have got some big robust middle men as well who can exploit flat and fast footy on the advantage line."
Gallagher Kangaroos Merit Team named
Former South Sydney GM of football Shane Richardson said the Rabbitohs were another team well positioned to take advantage of the rule changes after recruiting Queensland Origin forward Jai Arrow to join a mobile pack featuring the likes of Damien Cook, Cameron Murray and Jaydn Su’A.
He also suggested teams were more likely to use two hookers in tandem as Melbourne’s Brandon Smith and St George Illawarra’s Cameron McInnes had proved effective in a different role, as did Harry Grant for Queensland in Origin III.
"The big man’s game is diluted completely," he said. "Players like Damien Cook and Cameron Murray and Jai Arrow, they get at you with feet and because the ball is played so quickly you can’t come off the line and make a big tackle
"I think you are going to want guys who can play for longer periods. Brandon Smith played in the front row last year and Cameron McInnes played lock. If you’ve got another hooker in your club who is electrifying off the mark I can see them coming in to play that role."