Wallabies fullback Israel Folau is set to undergo surgery and will be out of rugby for a minimum of four months.

The Seven Network is reporting the dual international will have surgery on Tuesday on his troublesome ankle, having carried the injury and playing in pain through much of Australia's Rugby World Cup campaign.

Folau will have to pull out of a lucrative upcoming stint in Japanese rugby.

And, according to Seven, he will battle to be fit in time for the start of the NSW Waratahs' 2016 Super Rugby season.

Injured: Wallabies star Israel Folau. Credit:AP

AAP