After the postponement of Friday's ODI in Cape Town due to a positive Covid-19 test, the series is set to begin in Paarl on Sunday. The rest of the South Africa squad returned negative results on Saturday following a round of retesting.

Remember when ODI cricket was the priority? For England, at least, that was the case from May 2015 until the World Cup success of 2019. Every advantage, in selection and scheduling, was given to the 50-over format as England pursued their goal.

Those days are gone. And, with two T20 World Cups scheduled within the next 24 months, it may be a while until they return.

For that reason, it is two sides shorn of several of their stars which meet in this ODI series. For England, Jofra Archer, Ben Stokes and Sam Curran are rested, providing opportunities for some of those who could feature in three years' time. There are still eight men who played in the World Cup final in their squad, though.

South Africa aren't at full strength, either. But then they never are. The state of the economy - both cricketing and nationally - renders it enduringly hard for them to retain the services of their best players, but combine that with illness (there has been an outbreak of Covid-19 around the squad) and the need to fulfil transformation targets, they probably go into this series as underdogs.

And that's a bigger statement than it sounds. England have only once (at the end of 2009) won a bilateral ODI series in South Africa. England have also lost three of their four most recent ODIs and, in September, lost their first ODI series (omitting one-off matches) anywhere since the start of 2017 and their first at home since 2015.

Perhaps the most notable absence from the South Africa squad is Kagiso Rabada, who is injured. Pite van Biljon, Bjorn Fortuin and Reeza Hendricks have all been released to play four-day cricket. South Africa have also allowed Faf du Plessis, their most experienced player and highest ODI run-scorer of those currently available, to leave the squad. Bearing in mind he has the fitness of a superhero and has played around 15 hours of cricket in the last month, we can probably take the explanation of 'rest' with a pinch of salt. Instead, it seems younger players will be given an opportunity to claim a place in the side in the knowledge that du Plessis is now 36 and far from certain to make the next World Cup.

For both teams, then, the focus is on the future as much as the present. England will be hoping to find a 'new' Liam Plunkett - some would argue there's not much wrong with the 'old' one - with Olly Stone's pace and Reece Topley's left-arm angle and height potentially intriguing options.

And while Eoin Morgan, England's captain, insisted everyone involved was a viable option for selection for that next 50-over World Cup, there may be just a little doubt over whether Chris Woakes, now aged 31, and Moeen Ali, now aged 33, are going to last until 2023. Morgan, too, is 34 now and admitted that could be a factor.

"We don't know what our bodies will be like in two or three years' time," he said. "If 50-over cricket is going to continue to replicate 20-over cricket and the scores and intensity of the game continue to get higher, is that going to place more physical demand on every player? And if so, is a 36 or 37-year-old guy going to be able to fulfil the high-intensity standard of a World Cup?"

(last five completed matches, most recent first)

South Africa WWWLW
England LWLLW

You could almost see Quinton de Kock ageing by the moment during the T20I series. As if opening the batting against Archer and co wasn't demanding enough (it was actually Chris Jordan who dismissed him in all three games), he is also required to lead his side with the bat and remain on top of his game with the gloves. There is a huge amount demanded of de Kock and there are times - not least with the gloves, eg. the missed run-out of Dawid Malan in the final T20I - when it looks as if he is stooping under the weight of his burden.

England's strength in depth, at the top of the order in particular, is remarkable. But it does demand some careful management. At present, Jason Roy looks out of form and is enduring a bit of a grim run: his 10 most recent international innings (across T20I and ODI cricket) have earned him three ducks, three other single figure scores and a top score of just 24. There's little doubt the England management - and the England captain, in particular - will give Roy every chance of regaining his form; his long-term record remains outstanding and in his selfless aggression he has embodied many of the finer qualities of this team. But when you have likes of Tom Banton, Alex Hales, Dawid Malan and Ben Duckett breathing down your neck, the requirement to deliver is never ending.

Both Andile Phehlukwayo and David Miller have rejoined the squad, though they will need to undergo fitness tests to determine their availability for the first ODI. If they are fit - and the whispers about Phehlukwayo are encouraging - they should slot straight in. Janneman Malan is expected to open with de Kock after his strong performances against Australia and Jon-Jon Smuts and Kyle Verreynne will get opportunities in du Plessis' absence. South Africa could have as many as four spin options if Keshav Maharaj, Tabraiz Shamsi, Smuts and George Linde all play, while seamer Junior Dala could well take the new ball. After South Africa's third positive Covid-19 test on Thursday, they have 17 fit players in the squad to pick from.

South Africa (possible): 1 Quinton de Kock (capt, wk), 2 Janneman Malan, 3 Jon-Jon Smuts, 4 Rassie van der Dussen, 5 Kyle Verreynne, 6 David Miller, 7 Andile Phehlukwayo, 8 George Linde/Keshav Maharaj, 9 Junior Dala/Lungi Ngidi, 10 Anrich Nortje, 11 Tabraiz Shamsi

With no Stokes or Sam Curran, England do not quite have the all-round depth that has served them so well in recent times. For that reason, they may be inclined to include Tom Curran, despite his modest T20I series, or Moeen Ali as a second spin option at No. 7. A final decision will be made after a look at the pitch. Mark Wood and Olly Stone are set to provide a sharp pace attack with Sam Billings having earned himself a run in the middle order after an impressive display against Australia. With back-to-back matches on Sunday and Monday due to the rearranged schedule, England are likely to be extra careful in looking after their fast bowlers.

England (possible): 1 Jason Roy, 2 Jonny Bairstow, 3 Joe Root, 4 Eoin Morgan (capt), 5 Jos Buttler (wk), 6 Sam Billings, 7 Moeen Ali/Tom Curran, 8 Chris Woakes, 9 Adil Rashid, 10 Mark Wood, 11 Olly Stone.

Paarl proved a trickier proposition for the batsmen than expected during last week's T20I, with the boundaries noticeably more distant from the middle than at Newlands. A hot day is in prospect, which might aid purchase for the spinners as the game wears on.

Stats and trivia

  • Joe Root, playing his 150th ODI, requires 36 more runs to record 6000 in the format. He will be just the second England player, after Eoin Morgan, to do so, and if he gets there on Sunday, in his 141st innings, he will equal Viv Richards as fourth-fastest to the mark.

  • Chris Woakes requires one more wicket to become the sixth England player to claim 150 in ODI cricket.

  • South Africa have won 30 and lost 28 of their ODIs against England.

  • They have won six out of seven ODIs at Boland Park, with their only defeat coming against New Zealand in 2013.

"It purely comes down to execution. It's how you execute when you are under pressure. You can train as much as you want to in the nets but it's not the same intensity as in a game. It's identifying the big moment in the game, being able to stay calm in it and then execute."
Charl Langeveldt on the challenge awaiting South Africa's bowlers

"To say Jonny Bairstow only performs when he's angry is undervaluing him and not giving credit where it's due. We see Jonny as one of the best players in the world, particularly in the white-ball format. Jonny performs against the best sides in the world, he takes the best bowling line-ups in the world on and succeeds the majority of the time. We feel that he is one of our best players, so when we see him walking out to bat we are delighted to have him in our team."
Eoin Morgan defends his opening batsman after suggestions he needs to prove a point

George Dobell is a senior correspondent at ESPNcricinfo