South African cricket was rocked Thursday when it was announced that Test fast bowler Kyle Abbott had quit the national team in order to play county cricket in England. Cricket South Africa immediately cancelled Abbott's contract and said it was in the process of doing the same with one-day star Rilee Rossouw. Both have Kolpak contracts with Hampshire which preclude them from playing for South Africa. Abbott has signed for four years and Rossouw for three. The announcements came immediately after South Africa clinched a Test series against Sri Lanka, winning the second Test by 282 runs. Abbott will not play in the third and final Test in Johannesburg next week. "It's a massive loss," said South African captain Faf du Plessis, who was unaware of Abbott's decision until the player told his teammates during the Cape Town Test following a report from England about his impending move. Du Plessis said Cricket South Africa needed to take action to prevent a further player drain. Three other players — Stiaan van Zyl, Simon Harmer and Hardus Viljoen, who have all played Test cricket in the past 15 months — have also signed Kolpak deals recently. "We must make sure something like this doesn't happen again," said Du Plessis. "These players are too valuable and too important for us to sit back and say, these things happen and other players will take their place." Du Plessis acknowledged that Cricket South Africa's transformation targets, which effectively mean that a maximum of five white players can appear in a team, might have contributed to the exodus. "It's one of the factors," he said. "Opportunity, money — there are a lot of things that guys will look at as their excuse or their reason for going overseas. "What Kyle's reason is I'm not sure, but every single reason that is causing players to leave is a concern. We need to look at every one of them." Abbott, 29, became emotional as he told journalists that he had agonized over his decision. "At the end of the day it's the right decision for me." He said he had signed the deal five months ago and had planned to announce his international retirement after the third Test but brought it forward following the news leaking from England. He said that there was not a great difference in monetary terms between what he was earning from Cricket South Africa and what he will receive from Hampshire. "It's four years of security," he said. "I don't want to sit in 12 months time when everyone is fit, wearing a (reserve player's) bib again." Abbott was at the center of a major controversy when he was omitted from South Africa's team for the semifinal of the 2015 World Cup against New Zealand after team management was "reminded" of cricket's transformation targets. "I'm at peace with that," he said. "It was a very difficult time, not only for me but for the team and for Cricket South Africa. "I think it took us a while to get over that, as recently as the New Zealand Test series (last August) when we went back and had a culture camp. "Since then, not only has the team turned around but the issues the team had with various things regarding selection, whatever, have been addressed and the team and Cricket South Africa are on the right path." Cricket South Africa chief executive Haroon Lorgat said it was a "sad day" for South African cricket. "We invest huge sums of money in individuals. By way of example, Rilee has spent a lengthy period on the injury list while we spared no expense in providing him with the best medical support. Our Protea players are among the top five percent of earners in our country." Lorgat said Cricket South Africa was likely to place a limit on the number of Kolpak players who would be allowed to play in South African domestic cricket. "We must keep those spots open for South Africans who want to play for South Africa," he said. National coach Russell Domingo suggested he would not have picked them had he known they were leaving, and Cricket South Africa (CSA) said it was considering limiting the number of places in its domestic competitions for Kolpak players. In rugby union, South's Africa's resources have been decimated by similar departures though national selectors can pick overseas-based players. What is a Kolpak contract? — The Kolpak ruling came into force in 2003 when the European Court of Justice ruled that anyone with a work permit from a country which has an associate trading agreement with the EU had the same rights as a European worker. — The ruling originally related to Slovakian handball player Maros Kolpak who was released from his German club because of a quota on non-EU players. He claimed it was unfair and the court ruled in his favor. — A player becomes eligible for a Kolpak deal when he gives up the right to play for his country, and is not classed as an overseas-player signing. — Kolpak players need only a working holiday visa to play.