He will aid MultiChoice Diski Challenge mentor Duncan Crowie.
Ajax announced the news on Twitter, saying: 'The #UrbanWarriors are delighted to welcome former Bafana Bafana international David Nyathi back to Ikamva. He has been appointed as assistant coach to Young Ajax boss Duncan Crowie.'
Nyathi briefly served as an assistant coach to Muhsin Ertugral a few years back at Ikamva, while he also steered the Urban Warriors' Under-19 side to Metropolitan Cup success in 2013.
The 48-year-old enjoyed a fine playing career, earning 45 caps and representing the likes of Tenerife, St Gallen, Cagliari, Orlando Pirates and Kaizer Chiefs.