Klaasen played four Tests between 2019 and 2023, the most recent against West Indies last summer.

He is the second senior player to retire from the format after Dean Elgar's Test career came to an end with the New Year's Test against India. Klaasen was not part of that squad, after being dropped for Kyle Verreynne, but Test coach Shukri Conrad said Klaasen was still part of his plans.

No reason was provided for his retirement, but with commitments in the IPL, Hundred, and MLC, it is likely that Klaasen is pursuing T20 leagues in this phase of his career.

"After a few sleepless nights wondering if I am making the right decision, I have decided to retire from red-ball cricket. It's a difficult decision that I have made because it is by far my favourite format of the game," he said in a statement. "The battles that I faced on and off the field have made me the cricketer I am today. It has been a great journey and I am glad I could have represented my country. My baggy Test cap is the most precious cap I have ever been handed."

South Africa will play seven more Tests in 2024 - two each in West Indies and Bangladesh, two at home against Sri Lanka and one against Pakistan, but do not play any home Tests between January 2025 and September 2026. They will only play in two-match series for the 2023-2025 World Test Championship cycle and the scarcity of long-format fixtures is understood to be behind some players' needs to reprioritise their availability across formats.