The Team of Choice go into the game sitting in 16th place, while the Brazilians top the standings.
United have drawn their last four Absa Premiership matches, while Sundowns extended their unbeaten run to 11 games when they beat SuperSport last weekend.
The two clubs have met on 19 previous occasions, with the Pretoria team winning 13, while Maritzburg will be looking for a fourth win over Downs on Saturday.
United have won two of nine home matches against Sundowns, while losing on six occasions.
Sundowns have several ex Maritzburg players on their books, including Cuthbert Malajila, Mario Booysen and Rheece Evans, while United have former Downs men Kurt Lentjies and Kwanda Mngonyama in their ranks.