The former rugby league star has quit the NFL in the United States and will join Fiji's sevens team in London for this weekend's World Series finale.
Jarryd Hayne said Fiji reached out to him about being a part of their Olympic campaign and it was a chance he could not pass up.
But head coach Ben Ryan insists his place in the squad for Rio is not guaranteed.
A squad of 24 will assemble in June for training camp before being whittled down to a final 12, an exercise Ryan likened to Britain's Got Talent or the X Factor.
