Kosta Barbarouses and Oli Sail are unlikely due to recent injuries, but Tim Payne, Marco Rojas, Clayton Lewis and Storm Roux are among those who could come into the frame.
However, that is contingent upon the Australian border entry requirements, as any changes (due to the Omicron variant) may complicate the picture and preclude their travel.
"It may do," said Hay. "But it might not be from this part of the world - it could be from any country. We don't know what decisions are going to be made in the future around borders so we need to have a plan B and a plan C.
"That's why we are trying to communicate with a wider squad; we have got around 50 players that we are talking to on a regular basis, trying to keep [them] in the picture with the direction that we are going."
Adding to the uncertainty, Hay has to plan for March's Oceania World Cup qualifying tournament in Qatar, with the first two group matches played outside the Fifa window, which will likely exclude a number of European based professionals.
That won't affect his selection thinking for January – "I don't think it would be fair to drop players – or not bring players – because we are trying to go with the worst-case scenario" – but he concedes March will be a puzzle.
Hay has already ruled out Burnley's Chris Wood from the first phase of that OFC tournament – "with the level he is playing at, it's highly, highly unlikely that he would get released and we need to recognise that" but is optimistic the squad won't be completely bereft of first-choice options.
"We will have to name a much wider squad than normal," said Hay. "But it will depend on players and the state of their [club] season. We are quite hopeful that even given the challenges of March, we are going to have a strong squad."
After more than 10 weeks away, Hay returned home earlier this month, via a fact-finding mission to Scandinavia, an increasingly important base for Kiwi players, including Joe Bell, Marko Stamenic, Callum McCowatt and Elijah Just.
"It was hugely beneficial," said Hay. "Massive in terms of building relationships and connections with the key members at those clubs."
His next assignment is preparing for Jordan (ranked world no 91) and Uzbekistan (84), who will be tough opposition for the All Whites (110).
Jordan have played a staggering 22 games this year and toppled Saudi Arabia at the recent Fifa Arab Cup, while Uzbekistan assembled for 14 games in 2021 and pushed world No 18 Sweden away from home in September (1-2).
"They are going to pose some real problems, which is exciting because we are going to find out more about ourselves," said Hay. "That's really important for us; this group has got some potential but it is never going to be fully exposed until we come up against world-class opposition – that's what we are building towards."
All Whites Fixtures
All Whites vs Jordan, Abu Dhabi, 29 January
All Whites vs Uzbekistan, Dubai, 2 February
