having failed a medical with Celtic days before, Coetzee signed for Ajax's PSL rivals Mamelodi Sundowns on the transfer deadline day for a reported fee of R10m plus Mario Booysen.[6] He underwent corrective surgery on his foot soon after his arrival which resulted in him missing the entire 2017–18 South African Premier Division campaign. In August 2018, Sundowns coach Pitso Mosimane revealed that Coetzee's ailment was more serious than first feared and that "he can still stay two years without playing to get better".[ Coetzee made his international debut for South Africa in an African Nations Cup qualifier against Congo on 12 October 2014 making him the youngest player ever to represent the country, aged 17 years and 361 days – a record that was later broken by Supersport United forward Fagrie Lakay He was selected in South Africa's squad for the 2015 Africa Cup of Nations in Equatorial Guinea. In the nation's opening game, a 1–3 defeat to Algeria, he h