South Africa may have suffered more Cricket World Cup semi-final heartache but coach Rob Walter believes they have laid a platform for the future with a core group of players after exceeding expectations at the most recent tournament in India.

Poor starts with the bat and ball cost the side in their tense three wicket defeat to old foes Australia on Thursday – the fifth time they have exited a World Cup in the semi-finals.

South Africa will co-host the next 50-over finals with Namibia and Zimbabwe in 2027 and Walter believes there is much room for optimism they can improve further having arrived in India under the radar and with little expectation of success.

"I'm excited," he told reporters. "There's huge scope for us to grow as a team and to play even better than we have. The majority of the people that are going to be on the journey (to the next World Cup) are still in the changing room.

"We've seen young guys at the end of the tournament with less than 15 games to their name stand up and really dominate in certain phases for the team.

"Different people putting their hands up throughout the competition."

Wicketkeeper-batter Quinton de Kock announced he would retire from the 50-over format before the tournament started, while 2027 may be too far off for 34-year-old batters David Miller and Rassie van der Dussen, the core of the group should remain.

"We've seen guys play unbelievable cricket that probably surprised a lot of people in this (media) room and around the world. I think that is what fuels them to come back and be better," Walter said.

Former South Africa fast bowler Dale Steyn, who lost in the semi-finals in 2015, also believes there is cause for optimism.

"If you look at the stats overall, South Africa will walk away and say they ticked all the boxes they wanted to, but they just didn't get over the line," he told CricInfo.

"There will be some question-marks, but overall they were fantastic. I didn't think they would make the semi-finals when (fast bowler) Anrich Nortje was injured."