The increasing encroachment of T20 leagues on the international calendar could force South Africa to seek a postponement or field a second-string side on next year's tour to New Zealand. The two-Test series, which will begin on February 4 in Tauranga, will clash with the latter stages of the SA20, South Africa's T20 franchise competition and will present Cricket South Africa (CSA) with a conundrum over player availability.

A significant proportion of South Africa's Test players, including captain Temba Bavuma, new Durban Super Giants captain Keshav Maharaj and the entire frontline pace pack - Kagiso Rabada, Anrich Nortje, Lungi Ngidi and Marco Jansen - are contracted to teams in the SA20 and will either have to miss parts of the tournament or opt out of the Tests, with the latter more likely.

Although South Africa's players are contractually bound to both CSA and the SA20, CSA has guaranteed the SA20 first rights to the players over the January window and as such, the players will be obliged to play for their franchises rather than the national team. It is, therefore, almost certain that South Africa will have to send a makeshift Test side to New Zealand. CSA's CEO Pholetsi Moseki told ESPNcricnfo that the organisation will have a better idea of which players are available for the Tests, "after the SA20 mini-auction in September," and that they are still trying to have the New Zealand Tests moved.

The SA20 will begin in the week of January 7, after India's tour to South Africa, and should end around February 4. Ideally, CSA would have wanted the New Zealand Tests to be held from mid-February, but NZC was unable to accede to that because they are also due to host Australia, whose players need to be free by late March for the IPL. The three T20I and two-Test series against Australia runs from February 21 to March 12, while the IPL is understood to be pencilled in for after March 20 at the earliest.

CSA has also asked NZC to consider hosting the Tests during the IPL, in April, which would impact player availability for both sides, but this request could not be accommodated. Both CSA and NZC have players contracted to the IPL, though in South Africa's case it is far fewer than those who will be involved at the SA20. CSA maintains that they are still trying to find an alternative window to propose to NZC but "if you look at the FTP - there's nowhere to move the matches because we need to complete the WTC cycle by 2025," Moseki said.

Despite making that concession, the first season of the SA20 still faced scheduling difficulties. A World Cup Super League series against England had to be sandwiched into the tournament window and it had to move out of the Cape Town, Paarl and Port Elizabeth in order for those venues to ready themselves for the Women's T20 World Cup. As a result, the SA20 started off in the Western and Eastern Cape before fixtures were held up-country and on the east coast, and took an eight-day break after 22 matches to accommodate for the England ODIs.

The organisers were hoping for a smoother schedule this time around but, because of the clash with the New Zealand series, will have to wait until 2025 for that. Moseki said CSA has ensured there are no future issues in the SA20 window for the remainder of the ongoing FTP. However, South Africa are due to host Pakistan for two Tests, three ODIs and three T20Is deep into January in 2025, West Indies for five T20Is in January 2026 and England for three Tests, three ODIs and three T20Is in early 2027.

NZC has been contacted for comment.