Sri Lanka captain Angelo Mathews won the toss and elected to bowl in their must-win third one-day international against South Africa in Pallekele on Sunday.
The hosts, who trail the five-match series 2-0, made two changes to the side that suffered a four-wicket loss in Dambulla.
Batsman Dhananjaya de Silva and fit-again fast bowler Lahiru Kumara replaced Shehan Jayasuriya and Kasun Rajitha.
The Faf du Plessis-led South Africa made one change to their starting line-up, with top-order batsman Reeza Hendricks coming in for Aiden Markram.
Sri Lanka: Angelo Mathews (captain), Upul Tharanga, Niroshan Dickwella (wicketkeeper), Kusal Mendis, Kusal Perera, Dhananjaya de Silva, Thisara Perera, Akila Dananjaya, Suranga Lakmal, Prabath Jayasuriya, Lahiru Kumara
South Africa: Faf du Plessis (captain), Hashim Amla, Quinton de Kock (wicketkeeper), Reeza Hendricks, Jean-Paul Duminy, David Miller, Willem Mulder, Andile Phehlukwayo, Kagiso Rabada, Tabraiz Shamsi, Lungi Ngidi
Umpires: Raveendra Wimalasiri (SRI), Nigel Llong (ENG)
TV umpire: Paul Reiffel (AUS)
Match referee: Javagal Srinath (IND)