Israel Folau has been given a one-match ban for making contact with Peter O'Mahony in the air during Australia's defeat to Ireland last weekend.

Folau was shown a yellow card before being given a citing commissioner's warning following two separate incidents involving Ireland captain O'Mahony in Sydney, where the Six Nations champions won 20-16 to take the series 2-1.

The Australia full-back faced a World Rugby disciplinary hearing on Wednesday and was given a suspension that is set to rule him out of the Waratahs' Super Rugby clash with the Rebels on Friday.

Folau and Rugby Australia have until Friday morning to appeal against the decision. 

Waratahs coach Daryl Gibson earlier stated that the rules may need to be changed if Folau was slapped with a suspension.

"I hope it doesn't because that's the element of rugby that's important, that there is a kick and there is a fair contest for the ball," he said.

"I don't think in AFL they've got any particular rules governing that contest and so that's why for me it's really interesting, in terms of that law and what happens and the implications of what happens if he does get a sanction."

He added: "I believe if he does get some time, there's some real implications around the law-making process going forward.

"It really makes us look at the kick contest area and exactly how we can provide a law that provides for what is happening in terms of the collisions and guys landing on their heads."