Wales and Australia will receive no sympathy from Rugby World Cup organisers if their decision to pick only two specialist hookers in their squads backfires this month. Both nations will be told they must adhere strictly to tournament regulations regarding injured players and will risk potentially stiff sanctions if they do not possess sufficient front-row cover.

World Rugby – formerly the International Rugby Board – has made clear it expects all teams to have six front-row forwards in their match-day squads, two of whom must be able to fill the hooking role. If one of Wales’s two hookers – Ken Owens and Scott Baldwin – is injured within 48 hours of a game that would force one of Wales’s props to act as specialist cover.

England, who have named three hookers in their squad, are among those interested to see what would happen in such a situation. A World Rugby spokesman has emphasised that Law 3.5 requires any front-row replacement to be “suitably trained and experienced” but the Wales head coach, Warren Gatland, has yet to indicate precisely who would fit that bill in the event of his team experiencing a hooking crisis.

Any player dropped from a national squad cannot subsequently be reinstated later in the tournament and competition rules state individuals can be ruled out only on medical or compassionate grounds. If Wales, for example, wish to bring in a third hooker at any stage they can do so only if there is a tournament-ending injury to another squad member. They would also be required to submit a medical certificate to prove it.

In the event of Wales – or Australia – having one of their specialist hookers sent off or suspended there could also be significant knock-on effects, depending on circumstances. World Rugby declined to comment on hypothetical scenarios but it is understood no game would be allowed to commence with uncontested scrums occurring from the outset.

If teams were ultimately forced to go outside their nominated 31-man squads in order to fulfil safety requirements, however, they could expect a potentially tournament-ruining sanction such as pool stage points being deducted.

England’s head coach, Stuart Lancaster, has already expressed his personal belief that rival Pool A teams are walking a precarious tightrope. “I certainly wouldn’t have changed what we’ve done, no chance,” said Lancaster.

“I didn’t want to take that risk for the country. You have to have sufficient cover in the front row to make sure you have all bases covered.”

The Bath centre Jonathan Joseph, meanwhile, says he has a good feeling about his new England centre partnership with Brad Barritt before Saturday’s final warm-up Test against Ireland at Twickenham. “I feel very confident playing outside of Brad and I feel we can have a good relationship there,” said Joseph, conscious that Lancaster has now picked 13 different midfield starting pairings during his time in charge.

“I’ll play more of a playmaking role where Brad will be more of the hard runner. I see it to be more that sort of relationship, rather than Brad looking to distribute the way Kyle Eastmond does. You have to play to individual players’ strengths. Brad is a very strong ball carrier and a very strong defensive player so I think he’ll stick to that.”