France defence guru Shaun Edwards has shared his fears that disciplinary decisions are going to have a big impact on the outcome of the World Cup.

The World Cup warm-up matches have seen a number of yellow and red cards dished out as World Rugby’s referees clamp down on high tackles.

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The most notable of which saw Owen Farrell sent off against Wales, before a disciplinary hearing circus played out, with the England captain first cleared and then suspended after a World Rugby appeal.

Speaking to the MailOnline, Edwards said he believes up to eight teams are realistic contenders for the World Cup, but the most successful team will be the one that can keep their hands clean.

“Any of the top eight teams can win this World Cup, particularly now because yellow and red cards have such a major impact,” said Edwards.

“It’s a massive factor. They are taking over the game. I really feel for the players at times. It is hard for them, when someone drops their head very late and goes into contact.

Tournament hosts France open the World Cup on Friday, 8 September against New Zealand in Paris.

The All Blacks are coming off their biggest-ever loss in the final warm-up against the Springboks at Twickenham.

“New Zealand have been in really good form, but South Africa have really hit a peak now that they are putting their first team out for most of the games,” added Edwards.

Photo: Sylvain THOMAS / AFP