Udana's efforts have given Sri Lanka a chance to make a comeback in the fourth ODI.
South Africa have picked Aiden Markram and JP Duminy in the playing XI.
South Africa will be hoping that Aiden Markram and JP Duminy come good.
Amla, who was rested for the first three ODIs, will make way for Reeza Hendricks, who had originally been left out of the last two games.
Sri Lanka batsman Kusal Perera has been ruled out of the remaining two ODIs against South Africa due to a hamstring injury.
South Africa captain Faf du Plesiss has implored his batsmen to improve their standards.
Reeza Hendricks and Wiaan Mulder were left out of the South African squad for the fourth and fifth ODI of the Sri Lanka series.
Victory in the rain-hit match gave the Proteas an unassailable 3-0 lead in the five-game series.
De Kock, who scored 121, made batting look easy as he hit 16 fours and two sixes before being dismissed in the 31st over.
It took Rabada 64 matches to reach the milestone at an average of 26.80.