Cricket South Africa expressed disappointment on Tuesday at fast bowler Duanne Olivier's decision to sign a three-year contract with English county Yorkshire which will rule him out of international cricket.
Olivier, 26, was one of the stars of the South African summer, taking 31 wickets in five Test matches against Pakistan and Sri Lanka. He was man of the series against Pakistan after taking 24 wickets at an average of 14.70.
Cricket South Africa chief executive Thabang Moroe said Olivier had rejected a two-year contract with CSA.
"We find it extremely disappointing that Duanne has taken this step after all the opportunities we have given him, particularly over the past season and going forward, to live his dream of being an international cricketer," said Moroe.
"He was upgraded to a national contract during the current season on the strength of his outstanding performances in our Test squad and we offered him a two-year contract which would have given him financial security through to the end of the 2020/2021 season."
Moroe said Olivier's defection had implications for global cricket.
"This is not good news for the global game that a player who has just broken into the top 20 on the International cricket Council Test match bowling rankings for the first time should opt effectively to bring down the curtain on his international career in favour of playing only in domestic leagues," he said.
South African coach Ottis Gibson said he was also disappointed that Olivier had opted to play in England.
"He has been a key feature for us this summer and was without a doubt one of our standout performers. We held several meetings with him regarding his future with the Proteas throughout the summer and even offered him a two-year contract. To see him cut short a promising international career is disappointing. Ultimately, it was a decision we could not control despite our best efforts."
In announcing Olivier's signing, Yorkshire County cricket said on its website that the deal was subject to clearance through European Kolpak regulations.
Olivier meanwhile updated his Twitter profile to describe himself as a Yorkshire player. He was quoted on the county's website as saying it had been a difficult decision but that signing a long-term county contract was the best option for him and his family.
"It's giving up playing for my country with no guarantees of playing international cricket again," he told the website. "But at the end of the day, I needed to be true to myself. I've only got this one chance to see where my talent can take me and Yorkshire just felt right to me."
Olivier had a stint as an overseas player with Derbyshire last year and Yorkshire said it had beaten several other counties to get Olivier's signature.
Olivier follows several high-profile South African cricketers who have cut short their international careers by accepting Kolpak deals - which could come to an end when Britain leaves the European Union.
Fellow fast bowler Kyle Abbott joined Hampshire in 2017 at a time when he seemed set to become a regular member of the South African Test team, while batsman Rilee Rossouw was a first-choice one-day international player when he joined Hampshire at the same time.
Although Olivier made a major breakthrough this season, it was only because of injuries to other fast bowlers Lungi Ngidi and Vernon Philander. But his career record of 48 wickets in ten Tests at an average of 19.25 is outstanding.
As a white South African, Olivier was subject to a CSA target of six players of colour in national teams, which allows for only five white players - although the target is flexible depending on form and fitness. There were seven white players in the team beaten by Sri Lanka in the second Test last week.