The Rio 2016 and London 2012 champion must fight against compatriot and defending world champion Kiran Badloe to earn his place at this year's Olympics.

With each country only allowed one competitor at Tokyo 2020, many nations are using the World Championships at Sorrento Sailing Couta Boat Club to determine who they pick.

It means that the holders of the sport's two biggest prizes have been pitted against each other and must put their good friendship to one side.

The two regularly travel and train together, as well as sharing a coach, so know each other's tactics and methods.

"We have known this for a long time, so I am not worried about it now," Van Rijsselberghe, who has won the world title twice, said to NU.

"There is no point in putting energy into it either, because that is not going to make a difference."

Badloe added: "I don't think it would have been easier if I had disliked my competitor. 

"That seems rather tiring to me. 

"And I don't like it at all to suddenly distance ourselves from each other shortly before this World Championships. 

"We already knew that this was coming and that the interests would be very large. 

"We are not running away from that. "

Competition begins tomorrow on the waters of Port Philip Bay and will run until Saturday (February 29).

A fleet of 116 sailors from 31 countries are expected to compete in all.

Other entrants in the men's event include Italy's world number one Mattia Camboni and his compatriot Daniele Benedetti, the world number two.

France's Pierre Le Coq, who won bronze at both Rio 2016 and the 2019 World Championships in Italy, will also compete.

In the women's competition China's Yunxiu Lu is not defending her title due to the coronavirus outbreak, which means the world number one will be absent.

France's reigning Olympic champion Charline Picon will be a part of the fleet, as will Israel's world number two Katy Spychakov, the silver medallist behind Lu last year.

Russia's Olympic bronze medallist Stefania Elfutina is another name to watch out for.

As well as the battles between sailors from the same country, the event is also serving as the Oceania Olympic qualifier.

The highest ranked sailor from either Australia of New Zealand in each fleet will earn a quota spot for Tokyo 2020.

Australia seem to have the advantage as they have picked five men and two women, with just one New Zealander in each event.