The Welsh Rugby Union is considering extra matches at the Principality Stadium next season as it looks to boost revenue.
A Wales match against a Barbarians side is being planned for the opening weekend of November, a week after the World Cup final in Paris.
A Premiership match between Bristol and Gloucester is also being explored.
It would be the first time an English league derby would be held in Wales' national stadium.
Ospreys have also considered moving a league game to London from Swansea.
The Principality Stadium will host Wales' two World Cup warm-up games against England on 5 August and world champions South Africa two weeks later.
The Cardiff ground traditionally hosts four autumn international matches in November, but that does not happen in a World Cup year so the extra games would help the WRU's turnover.
League clash
The third round of United Rugby Championship (URC) league matches could clash with any potential Wales match against Barbarians with Scarlets hosting Cardiff in a Welsh derby in that round of games.
Any such Wales v Barbarians fixture could help pay tribute to former Wales lock and the world's most capped player Alun Wyn Jones.
The 37-year-old announced his international retirement before a potential fifth World Cup and has signed a short-term deal with Toulon to act as cover during the World Cup.
Whether Jones would be available for any 4 November fixture remains to be seen.
Wales faced the Barbarians after the 2019 World Cup in an uncapped match that was Wayne Pivac's first game in charge.
The Baa-Baas were coached by Warren Gatland that day in what was supposed to be his farewell after 12 years in charge.
Gatland has since returned to the Wales job after replacing Pivac in December 2022 and will lead the nation into his fourth World Cup in France later this year.
Scott Robertson, who will replace Ian Foster as the New Zealand coach after the World Cup, is being lined up to lead the Barbarians against Wales in this potential fixture.
Meanwhile, the traditional domestic double-header involving four Welsh regions, known as Judgement Day, has been pencilled in for 1 June 2024.
That is the final round of regular URC league matches with Scarlets hosting Dragons and Cardiff entertaining Ospreys.
Home venues were yet to be confirmed when the official URC fixture list was compiled last week, but nothing has been officially decided on whether Judgement Day will go ahead in the new season.