He also handed a first start to winger Kefentse Mahlo and prop Conraad van Vuuren as the competition continues again after the June break.
Mahlo takes over from Kriel, who moves to outside centre, while Serfontein will wear the 12 jersey for only the second time this season. Serfontein and Kriel played together in two of the three Springbok test matches in the recent Series against France.
Regular inside centre, Burger Odendaal, who played at numer 12 against the Hurricanes late last month, moves to the bench.
Van Vuuren, who has made three appearances off the bench, starts in his first match in place of Trevor Nyakane, who was ruled out, while John-Roy Jenkinson will take Van Vuuren’s bench duties.
Marais also opted to start Tony Jantjies at fly-half, with the former Junior Springbok running out in the starting team for the first time after three consecutive appearances off the bench. Tian Schoeman, who started against the Hurricanes, moves to the bench.
Marais made two changes to the starting pack. Nick de Jager is promoted off the bench and will start at number eight in place of the injured Hanro Liebenberg, with Renaldo Bothma and Shaun Adendorff coming onto the bench as lock and loose forward cover.
RG Snyman is also available again following his suspension and will combine with Jason Jenkins with Lood de Jager been ruled out.
Andre Warner could make his debut for the team after being named back-up scrum-half with Ivan van Zyl not available.
Bulls: 15 Warrick Gelant, 14 Duncan Matthews, 13 Jesse Kriel, 12 Jan Serfontein, 11 Kefentse Mahlo, 10 Tony Jantjies, 9 Rudy Paige, 8 Nic de Jager, 7 Jannes Kirsten, 6 Ruan Steenkamp, 5 RG Snyman, 4 Jason Jenkins, 3 Conraad van Vuuren, 2 Adriaan Strauss (c), 1 Lizo Gqoboka
Replacements: 16 Jaco Visagie, 17 Pierre Schoeman, 18 John-Roy Jenkinson, 19 Renaldo Bothma, 20 Shaun Adendorff, 21 Andre Warner, 22 Burger Odendaal, 23 Tian Schoeman