South Africa are without fast bowler Kagiso Rabada but Maharaj added: “The preparation has been very good. We had two constructive warm-up games and the boys have acclimatised nicely to the heat and they are excited to go.”
England captain Jos Buttler said: “We would have batted first too, it looks a very good surface and is obviously a very hot day.”
World Cup-winner Stokes, now England’s Test captain, was bowing out of the 50-over format on his Durham home ground of Chester-le-Street after announcing a shock decision to quit 24 hours earlier.
Stokes, 31, is making his 105th and final ODI appearance having come to the conclusion that the relentless demands of England’s schedule have stopped him contributing as he would like across all three international formats -- Tests, ODIs and Twenty20s.
“It’s going to be an emotional day for us and for Ben (Stokes) in his last game and on his home ground too,” said Buttler.
“Hopefully we can send him off with a win.”
Fifty-over world champions England made three changes to the side that suffered a five-wicket defeat by India in the third ODI on Sunday, a result that condemned them to a 2-1 loss in the three-match series.
England gave an ODI debut to Matthew Potts after the fast bowler won his first Test cap against New Zealand last month.
Leg-spinner Adil Rashid returned to the team after completing the Hajj pilgrimage and seamer Sam Curran was recalled.
The trio replaced the in-form Reece Topley, rested on workload grounds, fellow left-arm quick David Willey and paceman Craig Overton.
England: Jason Roy, Jonny Bairstow, Joe Root, Ben Stokes, Jos Buttler (c/wk), Moeen Ali, Liam Livingstone, Sam Curran, Adil Rashid, Brydon Carse, Matthew Potts
South Africa: Janneman Malan, Quinton de Kock (wk), Rassie van der Dussen, Aiden Markram, Heinrich Klaasen, David Miller, Andile Phehlukwayo, Keshav Maharaj (c), Anrich Nortje, Lungi Ngidi, Tabraiz Shamsi