Petrie, who captained the development side in the 33-15 defeat to the NSW Waratahs, was taken to the Royal North Shore hospital after feeling what coach Matt Williams described as a "crack" to the neck.

Scans determined that while he had taken a knock, there was no permanent damage and Scotland's doctor James Robson is confident Petrie will be fully fit in "two or three days".

That would leave the 27-year-old, who started amongst the replacements against Samoa last Friday, available to play Australia on Sunday - even if it means he has to be bracketed in the initial squad selection.

Meanwhile, Bath winger Simon Danielli will be returning back to the UK after finally succumbing to a back injury that has dogged him all tour.

Danielli has sat out large swathes of training in the last fortnight and was again replaced at half-time against the Waratahs.

Williams, who must decided on 10 players to send home, confirmed after the game that the injury had caught up on Danielli, who would have been pressing for a start in the side if fit.

Scotland have already lost Paterson, Tom Philip, Robbie Kydd, Cameron Mather and Euean Murray from the tour.