World Rugby confirmed on Thursday that the Johannesburg-born 29-year-old fulfilled the necessary ‘birthright transfer’ requirements.

The regulation – which came into force at the start of 2022 – allows for players to be selected for their country of birth (or of their parents’ or grandparents’ birth) once a period of at least 36 months has elapsed since last selection for an adopted country.

The former DHL Stormers and Western Province lock moved to Ireland in 2016 and qualified for selection for that country by residency in 2019. He was picked for his adopted country’s Rugby World Cup squad that year and made five appearances. He has not been selected subsequently.

The 2,03m second rower has made more than 130 appearances for Munster and was a part of their Vodacom United Rugby Championship-winning team in Cape Town last month.

Kleyn has been in camp with the Springbok Castle Lager Rugby Championship training squad and is now eligible for selection as early as next month when the Springboks’ 2023 season kicks off against Australia at Loftus Versfeld.