Superstar fullback Israel Folau has been ruled out of the NSW Waratahs’ Super Rugby showdown with the Sharks after copping a knock to the throat.

The NSW Waratahs have suffered a major blow with tryscoring freak Israel Folau ruled out of this weekend’s Super Rugby showdown with the table-topping Sharks in Durban.

Folau has a bruised throat and, after visiting a specialist on Monday night, Waratahs officials are refusing to risk their most valuable commodity on a long-haul flight to South Africa.

The dual international will return to the specialist on Thursday and is also in serious doubt for NSW’s second match in the Republic against the Stormers in Cape Town.

Folau copped a knock to the throat in the 20th minute of the Waratahs’ 32-8 victory over the Melbourne Rebels on Friday night, but it didn’t stop the superstar fullback from playing on and posting a second-half tryscoring double.

But he was barely able to talk after the game and the swelling has still not subsided.

Folau’s brace against the Rebels took his tryscoring haul to eight five-pointers from just four matches in 2014, the most prolific first-month return by any player in 18 years of Super Rugby history.

He has scored more than half of NSW’s tries so far this campaign and his absence will leave a big void in the Waratahs backline against the Sharks.

Coach Michael Cheika has a wealth of options at his disposal, but is likely to shift former Wallabies No.15 Kurtley Beale to fullback and promote ex-Test star Rob Horne for a start in the centres.

Former Queensland Reds centre Jono Lance is also in the touring squad and could come under consideration for a start.

The Waratahs are currently third on the Super Rugby ladder and second in the Australian conference behind the Brumbies.