James Tedesco is expected back for Australia against Fiji at Suncorp Stadium next Sunday, after coach Kevin Walters rested him for the World Cup opener.
Walsh credited Tedesco with helping him prepare for his return in Australian colours on Thursday night.
Walters had chosen Walsh at fullback over Tedesco, who had won the Clive Churchill Medal in the Roosters' premiership victory just a week earlier.
Walsh scored a breathtaking try in Australia's 24-22 victory over New Zealand, but vomited during the match again.
He said he was prepared to pay "top dollar" to consult any specialist who could help prevent the problem.
Walters said Tedesco would play against Fiji and explained he wanted him rested after a busy NRL finals campaign.