Pretorius had fractured his left thumb in the third T20I against India, which was South Africa’s only win in the three-match series. Jansen, 22, who was only part of the T20I squad for the tour, then replaced Pretorius for the ODI leg before being named for the T20 World Cup, which starts on October 16 in Australia.
Wayne Parnell, Anrich Nortje, Kagiso Rabada and Lungi Ngidi are the other seam-bowling options in the South Africa side for the tournament apart from Jansen.
South Africa open their campaign on October 24 against one of the qualifying sides from the first round.
Updated squad: Temba Bavuma (capt), Quinton de Kock, Reeza Hendricks, Marco Jansen, Heinrich Klaasen, Keshav Maharaj, Aiden Markram, David Miller, Lungi Ngidi, Anrich Nortje, Wayne Parnell, Kagiso Rabada, Rilee Rossouw, Tabraiz Shamsi, Tristan Stubbs
Reserves: Bjorn Fortuin, Andile Phehlukwayo, Lizaad Williams