Twenty-year-old Lungi Ngidi, who has taken six wickets in his first two T20 Internationals, has earned a maiden call-up to South Africa's ODI squad for the first three matches against Sri Lanka, which start on January 28. AB de Villiers, who has not played an ODI for South Africa since June last year, because of an elbow injury, will return to lead the side while Chris Morris, who missed South Africa's last ODI assignment against Australia in October with a knee problem, is also back.

Kyle Abbott and Rilee Rossouw - who were also part of the 5-0 win over Australia - could not be considered because both have signed Kolpak deals while Dale Steyn remains sidelined as he recovers shoulder surgery.

South Africa's attack is also without Morne Morkel, who has not played for them since June when he sustained a back injury. Morkel has been on the comeback trial since August but his progress has been especially slow and concerns over his future are growing. Left-arm spinner Aaron Phangiso was left out in favour of left-arm wrist spinner bowler Tabraiz Shamsi, as South Africa trial combinations ahead of the Champions Trophy.

South Africa have 10 ODIs in the next six weeks in preparation for the tournament, followed by three more matches in England in May and convener of selectors Linda Zondi is confident they will be ready. "We can't ask for more in terms of preparation. Our one-day squad is coming together really nicely and we are especially happy that we have AB de Villiers back as captain," Zondi told ESPNcricinfo.

De Villiers will take over from Faf du Plessis, who led South Africa against Australia and has succeeded de Villiers as Test skipper, with a view to taking the team to the 2019 World Cup which he has described as a "top priority." So much so that de Villiers had opted out of Test cricket for most of 2017 in order to manage his workload ahead of the next World Cup. CSA CEO Haroon Lorgat confirmed de Villiers will be obliged to play in every ODI leading up to that event.

He will hold together a well-oiled batting line-up which will see Hashim Amla, no longer under threat from Rossouw, and Quinton de Kock open while du Plessis, Duminy and David Miller make up the rest of the top six. Farhaan Behardien, who was made T20 captain for the ongoing three-match series against Sri Lanka that will be decided on Wednesday, is the reserve batsman in the squad.

South Africa have four allrounders in their squad in Morris, Wayne Parnell, Dwaine Pretorius and Andile Phehlukwayo and Zondi was particularly excited about the depth they will add. "If you just think back to a few years ago, we were talking about how much we were struggling to move on from Jacques Kallis and how the cupboard was bare, but now we have a lot of choice. The same can be said for the spin department. For the first time in years, we have three or four different players to choose from."

Legspinner Imran Tahir remains South Africa's No.1 choice but has received assistance from Phangiso in the T20 series and now Shamsi in ODIs. Zondi said Test spinner Keshav Maharaj was also on the radar. "We're not at all saying Phangiso should only play T20s and Shamsi only ODIs. We just want to see how this combination works out and then we will take it from there," Zondi said.

But the most important experiment will be with the new ball. In Steyn and Morkel's expected absence, Abbott was being earmarked to open the bowling at the Champions Trophy and Russell Domingo even lamented the lack of time South Africa have to find a suitable replacement when it was revealed Abbott's international career was over in the first week of January. Now, Ngidi has emerged as a candidate to partner Rabada at the tournament.

Ngidi bowls quickly, aggressively and accurately but Zondi does not want to put too much expectation on him just yet. "We need to take it one step at a time with him and see how he develops but we are very pleased with what we have seen so far. To have guys like Ngidi, Dwaine Pretorius and Andile Phehlukwayo coming through proves to us that our pipeline is producing."

Firdose Moonda is ESPNcricinfo's South Africa correspondent