Cooper Vuna and Afa Pakalani have been playing club rugby in Sydney (Shute Shield), Afa Pakalani has already stated he feels its too early in his career and He doesnt want to jeopardise his contract with the Waratahs.
Cooper Vuna would be in the same situation. His cross code signing was one of the biggest transfers during the off season id imagine He would not want to jeopardise his chances of playing Super Rugby.
No word on Piutau , He will be playing for Counties Manukau in the ITM Cup. Seeing Sona Taumalolo turn out for Tonga must mean players from New Zealand are free to play for their respective countries. Seeing as Piutau hasnt shown is a strong sign He will not be turning out for Tonga.