Quinton de Kock has withdrawn from his proposed stint with Nottinghamshire at the request of Cricket South Africa.
De Kock had been scheduled to appear in four Specsavers County Championship matches at the end of the season.
His withdrawal leaves Nottinghamshire's director of cricket Mick Newell on the hunt for a replacement for a county currently lying third in the table, 43 points behind the leaders Surrey.
Cricket South Africa have indicated that de Kock has a reoccurrence of an injury to a right index finger that he sustained during the New Zealand series and that the management has decided to pull him out to allow the injury to heal ahead of a busy season.
However, he has been promoted to captain for the last two matches in South Africa's one-day series against Sri Lanka, even though the series has already been won, suggesting that the injury is not all that serious.
De Kock's withdrawal follows a disturbing pattern for county cricket this summer of national Boards pressing players to withdraw from confirmed deals, often more because of a change of heart than change of circumstance.
Yorkshire lost Australian Billy Stanlake at the last moment from their Vitality Blast campaign and the will-he-won't-he saga of Virat Kohli and Surrey finally ended with him not fulfilling his brief county deal.
"We're disappointed because Quinton is a high-quality player and we would have been stronger with him in the side, but he has a central contract with Cricket South Africa and there is always some risk when you sign a player of his profile," said Newell.
"We would like to strengthen the team for the remaining red ball fixtures and will consider the options that are out there but it's a particularly tough market at this stage of the season.
"If there's something that can be done then we'll explore it but there isn't a long list of available overseas talent."