Eleven Kangaroos players are set to become free agents on November 1, including Cameron Munster, Harry Grant, Latrell Mitchell, Bradman Best, Jack Bostock, Isaah Yeo and Liam Martin.
Contract uncertainty has surrounded Sam Walker and Hudson Young after their NRL clubs withdrew lucrative offers. If they do not resume negotiations, they will also enter the market.
Martin said the situation had not unsettled Walker. "We were all a bit shocked by it, but he's been great," he said. "He's been upbeat."
Walker was named in Australia's No. 20 jersey on Tuesday, with hometown favourite Tom Dearden chosen to partner Munster against the Cook Islands.
The Kangaroos are preparing in Townsville for Saturday night's match at Queensland Country Bank Stadium. They remain unbeaten after facing New Zealand and Fiji, though their performances have not been convincing.
Martin said contract talk had become a source of team banter. "We're all getting into one another, going, 'Oh, where are you looking at on realestate.com'," he said.
The second-rower said staying at Penrith, where he has won four premierships in eight seasons, was his preferred outcome. He said, "I absolutely love being there," and hoped to agree a deal.