Cape Town - Lungi Ngidi could be among South Africa’s main weapons at the World Cup, according to his captain Faf du Plessis.

Ngidi opened the bowling against Sri Lanka in Cardiff in a warm-up match on Friday and took two wickets in an incisive four-over opening spell

And Du Plessis believes that is just the beginning of what the big fast-bowler has to offer. 

"I rate Lungi very highly. He is an exceptional fast bowler who is going to get wickets for us," Du Plessis told media after the match. 

Though Du Plessis would have liked to see Ngidi bowl "seven or eight overs straight," he capped the quick’s participation to six overs to give "everyone a good run out." 

The match also saw Kagiso Rabada make a return from a back injury that resulted in his early departure from the IPL and Chris Morris come back into the national side after his late inclusion in the World Cup squad. Du Plessis hopes to see both improve as the tournament goes on. 

"KG has been slowly building up, working on his action and working on his run-up. Today was the first time with he was bowling at full intensity," Du Plessis said. 

"Chris Morris was a bit rusty, he hasn’t played much cricket but he still has time to try and get over that rustiness."

Morris will be competing with Phehlukwayo and Pretorius for a place in the final XI, with du Plessis confirming that there is "definitely not space for three," allrounders. 

There may be room for two, but that would depend on the fitness of Dale Steyn, who is "progressing," from a shoulder injury. 

Should Steyn be fit, South Africa may only have room for one allrounder in their final XI to accommodate the full variety of all their frontline seamers.

"If our fast bowlers are all fit, we love that diversity in that attack," Du Plessis said. 

South Africa also have plenty to ponder in their batting line-up, with a middle-order that currently includes JP Duminy, David Miller and Rassie van der Dussen. 

Only van der Dussen scored significantly in the Sri Lanka match (40 off 41 balls) and his versatility could see him slot in anywhere in the line-up. 

"Rassie has been exceptional for us the last 12 months. He fits in extremely well into any position: No 3, 4 and 5. He has put his name down for any of those positions," Du Plessis said. 

At the top of the order, Hashim Amla restated his case for a position with his highest score since January, something du Plessis couldn’t have been more pleased about. 

"Today was beautiful to see Hash play, the way Hash plays: quietly killing the bowling attack," Du Plessis added. 

The only person left for South Africa’s captain to mention was himself. He top-scored with 88 off 69 balls and demonstrated a new level of confidence in his approach, which he hopes his team can emulate. 

"It’s important to try and let my actions back up my words. I feel if I am asking the batting unit to play with more freedom, not to fear failure and to be courageous, then I have to do it when I bat out there in the middle," Du Plessis said. 

"I feel like the last year I have improved that aspect in my game. I have to keep making sure I lead with that."

The Proteas are next in action when play West Indies in their final warm-up match in Bristol on Sunday.