Manchester - "I don't know, to be honest with you."

Those were Proteas captain Faf du Plessis' words when asked at Old Trafford on Saturday exactly what needs to happen for South Africa to finally win a Cricket World Cup

Since 1992, they have now tried and failed eight times without ever getting to a tournament final. 

Their efforts in 2019 were about as disappointing as they could possibly get, with three wins from nine and a 7th-place finish the harsh reality. 

This time around, the Proteas couldn't even put themselves in a position to be on the receiving end of the inevitable knockout heartache that has been such a hallmark of their participation at the global showpiece over the years and decades. 

Du Plessis, though, doesn't shy away from a tough question and he took a few moments to think deeper about his answer.

"In the last two years with this team, we've always struggled a bit with balance," he said.

"We were always a batsman light or a bowler light, so I'm hoping in four years' time that will sort itself out.

"The perfect combination team-wise is when you have got a sixth bowling option and you have got a top seven plus maybe an 8 or a 9.

"If you look at the teams that are here, a lot have that. They have got a great balance, a long batting line-up, great pace."

Having a strong fast bowling unti, Du Plessis adds, has been key in England. 

"I think you could see the success of this tournament has been the fact that the teams that have done well has got fast bowlers in their team," he said, making reference to Mitchell Starc, Jofra Archer and Lockie Ferguson.

"I'm so glad for KG (Kagiso Rabada) today. KG showed what makes KG the world's best. He was at his best again today.

"That first couple of overs to David Warner was like the Test series in South Africa when he was pumped up and bowling at him so great to see him back at his best."

Rabada finished with figures 3/56 from his 10 overs on Saturday for his best return of the tournament, and looking ahead Du Plessis was hopeful that South African cricket would find support for its strong pace bowling stocks. 

With the next World Cup in India, Du Plessis also spoke about the importance of playing spin and also having spin bowling options in the bowling attack. 

"I think right now we have three or four really good players of spin and you have some young guys that have got time on their side to get better, so that will be the difference between doing well or not," he said. 

Player management, Du Plessis added, was also key for a World Cup. 

The Proteas had wanted their IPL players to play a limited role in this year's tournament to ensure that they were well rested for the World Cup, but Dale Steyn got injured on duty for the Royal Challengers Bangalore while Rabada also pulled up with a back strain. 

Having eight days off before Saturday's 10-run win over Australia, Du Plessis said, helped. 

"I think it was a good example once again that it is something we need to learn from, from a team point of view, that if there is an opportunity to make sure that players can get rest, especially before a tournament like this going forward, we need to take it," he said.

"I think in all sports you are your best when fresh mentally because it's that extra 10 percent which we probably lacked in the first seven games.

"It's the battle of the mind and then that's possibly something that we can learn from."

@LloydBurnard is in England covering the 2019 Cricket World Cup for Sport24 ...