Wales are in talks to face world champions South Africa at Twickenham in the final week of June.
The game would be a warm-up before Wales’ two-Test series in Australia in July, while the Springboks are hosting Ireland on the same weekends.
South Africa defeated New Zealand at Twickenham in a World Cup warm-up match in August 2023.
The Springboks went on to retain the World Cup by beating the All Blacks in the final in Paris.
Wales were comprehensively beaten 52-16 by South Africa in another World Cup warm-up match in Cardiff last August.
The Principality Stadium is not available this summer because the match is taking place during the Cardiff concert season, with the Foo Fighters playing at the ground on 25 June.
South Africa have confirmed they will play Ireland on 6 July in Pretoria before another Test in Durban seven days later.
Wales travel to face Australia on the same dates but the venues of Melbourne and Sydney are yet to be officially confirmed.
The Wales and South Africa match in London would be held the weekend after the United Rugby Championship (URC) final.
Wales are also exploring the possibility of a fourth summer international in July, which would be staged the weekend after the second Test against Australia. This game would not be against the Wallabies.
