Wales have opened talks about moving their big autumn internationals to either Cardiff City Stadium or the Liberty Stadium.
Wales' Principality Stadium home is off-limits after being transformed into a 1,500 bed field hospital as the country tackles the coronavirus pandemic and that contract has been extended until at least September.
It is likely to mean Wales need a new home for the postponed Six Nations clash with Scotland, then the November Tests with New Zealand, South Africa, Fiji and Argentina.
WRU chairman Gareth Davies confirmed tentative discussions had started about moving matches to the home of football clubs Cardiff City and Swansea City.
He said the WRU would rather play at rugby grounds and cited Llanelli’s Parc y Scarlets as an option, although that too is being used as a field hospital.
Rugby, of course, is also played at the Liberty with the Ospreys ground-sharing with Steve Cooper's Swans.
But the WRU will explore a variety of options and playing at Cardiff City Stadium would enable them to stay in the capital.
Confirming contingency plans were being examined Davies told the BBC: “We will discuss it with rugby grounds,” before saying: “The Liberty Stadium and Cardiff City Stadium could be other options.
“Those tentative discussions are in place. It is an incredible situation. In your working career you always come up against challenges but there is normally a clear way through.
“This issue sadly has no ending because there are so many variables and unknowns. The likelihood is there won’t be any huge gatherings."
Wales have history of playing at football venues, using Wembley as a temporary home between autumn 1997 and the spring of 1999, when the Millennium Stadium was being built.
They also beat the Barbarians 42-0 at Bristol City’s Ashton Gate in 2004 and have staged full internationals at Wrexham’s Racecourse Stadium.
Moving to Cardiff City Stadium or the Liberty would present challenges of its own, with the Bluebirds and Swans also needing to cram in their own fixtures.
Switching the Six Nations match with Scotland, which was postponed the day before it took place, would also pose particular problems for the WRU.
They banked the ticket money from a 74,000 sell-out and would presumably have to refund it and reimburse hospitality packages. Home Six Nations matches are believed to be worth around £4m to the WRU.
Cardiff City Stadium holds 33,000 fans and the Liberty 20,000. But matches could yet be played behind closed doors, which would give the WRU further options - although any stadium they use would have to be up to international standard.