NSW Waratahs hooker Tatafu Polota-Nau has been ruled out of Saturday's Super 14 semi-final against South Africa's Sharks in Sydney with a sprained hand.

Polota-Nau (pictured) left the field during the Waratah's 18-11 victory at Queensland Reds last Saturday but hopes to be available for the final if the Waratahs beat the Sharks.

"My hand's swollen so I can't throw or bind at the moment, but I'm confident the guys can do the job on Saturday and hopefully I'll be right for next week if we get through," Polota-Nau said.

The Crusaders host the Hurricanes in the all-New Zealand first semi-final in Christchurch with the Waratahs, who finished second in the end of season standings, facing on the Sharks in Sydney soon after.

The final takes place on May 31 and the venue depends on which teams make it through the semis.

Reuters/Terence O'Rorke / Eurosport