Cardiff - The Proteas go into Saturday's must-win World Cup clash against Afghanistan in Cardiff with fast bowler Lungi Ngidi still a major fitness concern. 

The 23-year-old has not played since he left the field after just four overs of South Africa's second match against Bangladesh at The Oval back on June 2. 

Since then, the Proteas have lost Dale Steyn from their squad with a shoulder injury, while Beuran Hendricks was drafted in as Steyn's replacement. 

After leaving Ngidi out of the starting XI for the washed-out clash against the West Indies in Southampton on Monday, skipper Faf du Plessis expected him back for the Afghanistan. 

The word out of the Proteas camp on Friday afternoon, however, was that Ngidi could face another match out. 

"He is still doing some work, today and possibly even tomorrow," Du Plessis confirmed.

"It's a tricky one with hamstring strains, particularly with fast bowlers, to know when they are ready.

"We'll make a decision on that tomorrow."

If Ngidi doesn't play, Hendricks will certainly be included. 

While the Proteas have returned woeful results in the tournament so far - they are winless after four matches - they will still be expected to be too strong for Afghanistan, with or without Ngidi. 

Du Plessis acknowledged that planning for the long-term was part of his thinking in deciding whether or not to rush Ngidi back. 

"It's a tricky one because we're in a position now where we have to win five games out of five, so you want to have your best guys available for selection," he said.

"If he is not 100% or even 90% ready for the game and there is a bit of rain around ... is it worth the risk?"

"Those are the conversations that we have been having, so it's probably the right call if he is not ready to give him a little bit of time and see if he can play the next four games, which are obviously going to be big when we play against the bigger nations.

"Beuran is bowling nicely in the nets ... he looks like he's bowling very well."

Play on Saturday is set to get underway at 14:30 (SA time). 

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