Anrich Nortje and Sisanda Magala will undergo fitness tests this week to determine their availability for the ODI World Cup. They were named in South Africa’s initial 15-member squad for the tournament, but played only one fixture each of the five-match ODI series against Australia, before sustaining lower-back and left-knee injuries respectively. A final call on their inclusion will be taken before South Africa leave for India on September 23 with early indication that they are both at risk of not making the trip.

“We are continually taking stock as to where both of those players are,” Rob Walter, South Africa’s white-ball coach said following the team’s 3-2 series win over Australia. “The fact that they weren’t playing today with a week to go before we board the plane for the World Cup is obviously a cause for concern. We would have wanted them out there. There are complications around taking players that are injured into a World Cup because then you have to provide a medical reason to be swapped out.”

If Nortje’s absence is confirmed, it will be a major blow for South Africa as he is their quickest bowler, with substantial experience in India, where he plays for Delhi Capitals in the IPL. Nortje played in the Major League Cricket tournament in USA over the South African winter and was rested for the T20Is against Australia. He was then ruled out of the first ODI but played the second. He managed to bowl only five overs before leaving the field. He missed the third game after he was sent for scans and was then ruled out of the series, but was due to begin bowling again with the coaching staff this weekend.

Magala’s issue also appears serious. He had not played any cricket since splitting the webbing in his hand at the IPL in early April and was subsequently ruled out of the T20Is against Australia with infrapatellar tendinopathy – pain in the tendon that connects the kneecap to the shin bone. He played in the third ODI against Australia, where he bowled four overs, and has since experienced discomfort in the knee again.

Should either Nortje or Magala be ruled out of the World Cup, South Africa are likely to call up Andile Phehlukwayo, who has made his way back despite losing his national contract earlier this year.

Phehlukwayo played in the second and fifth ODIs against Australia. While he did not make much of an impression in the first game, he scored 38 off 19 balls to finish the innings strongly in the series finale and then took 1 for 44.

“Andile is one of a couple of guys who are part of a broader squad and today he showed us, especially with the bat, what we have seen in terms of his capability,” Walter said. “That knock, you can look at it, and say it was match influencing. A total of 270 looks different to a total of 315 and he was a massive role-player in that. He took an important wicket with the ball as well. I am very happy that Andile was able to deliver that performance today.”

South Africa’s conundrum will be what to do if both Nortje and Magala are ruled out of the World Cup, especially as Kagiso Rabada experienced ankle discomfort and had to sit out the final ODI. There are other niggles among the back-ups. Wayne Parnell – not part of the World Cup squad – is nursing an elbow injury after also picking up a shoulder niggle and has not played for his domestic side, Western Province, but ESPNcricinfo understands he is recovering well from both. Another candidate is Lizaad Williams, who played in the T20I series but has just one ODI cap to his name and does not have Nortje’s pace or Magala’s death-bowling reputation. “Lizaad is part of the T20 group and that’s really it,” Walter said.

Walter also mentioned left-arm spinner Bjorn Fortuin, though calling him up would change the make-up of South Africa’s squad, which is heavily reliant on fast bowlers.