Age, experience and expertise have done little to ease Marizanne Kapp's nerves ahead of the opening match in the Hundred.

Kapp, the 31-year-old veteran of nearly 200 international matches across formats and ranked as the world's leading ODI allrounder, is part of a formidable three-pronged South African contingent who will turn out for Oval Invincibles against Manchester Originals in the first match of the tournament at the Kia Oval on Wednesday night.

"To be honest, I'm really, really nervous," Kapp told ESPNcricinfo. "We had our first training match yesterday, it's definitely something to get used to but once you understand it, it's quite exciting.

"I'm usually someone who gets nervous but the quarantine adds to that because obviously now you didn't really train cricket for two weeks and the uncertainty of the new format just makes you nervous because you want to do well."

Of comfort to Kapp is the fact that she is joined by Shabnim Ismail, with whom she regularly opens the bowling for South Africa, and Dane van Niekerk, Kapp's wife of three years who captains her country and will also lead Invincibles. But the road hasn't been the easiest to this tournament, postponed since last year because of the Covid-19 pandemic.

Following their 4-1 ODI series victory in India in March, the South Africans returned home, then made their way to England via a two-week quarantine period in Croatia, which involved one week confined to their rooms. Another five days' quarantine once in England whereby they could train but not mingle with their team-mates meant they had to play a practice game on Monday whilst keeping their distance and the first time they will have normal contact with the rest of the team will either be on the eve of the first match or game day itself.

"I'm someone who, if I don't hit 1000 balls or bowl 200 balls then I feel like I'm not prepared"
Marizanne Kapp

During that training match, Kapp found herself bowling at the death with her side behind on over rate and with the resultant penalty of having only three rather than four fielders outside the circle. Combined with having 20 fewer balls to play with, the format poses real conundrums for bowlers, said Kapp, who is also a seasoned franchise player, having featured in the KSL and played six WBBL seasons with Sydney Sixers before signing with Perth Scorchers for the next edition.

"It's really challenging," she said. "I told one of the coaches yesterday, my preparation is key and I felt so good leaving South Africa because I worked hard and then you go into quarantine and you lose a bit of rhythm.

"Now I'm stressed because you didn't hit enough balls or you didn't bowl enough balls and it's a new format and Covid and the quarantines are a massive headache for me.

"They just kept on telling me, 'look you're so experienced, you've been playing so many years, you'll be fine'. I'm someone who, if I don't hit 1000 balls or bowl 200 balls then I feel like I'm not prepared but actually, I was decent yesterday, if I can say it that way."

It's hard enough on the bowlers, so spare a thought for the captains.

"I told Dane last night that I feel sorry for her because she was also in quarantine, so I know how I feel if I didn't prepare as well as I would have liked, and now you put captaincy on top of that and a new format," Kapp said. "I don't know how she does it but we'll see how it goes tomorrow.

"This whole competition is going to be a challenge because we're so used to being in our comfort zones and this is the complete opposite... when she's there, you immediately feel a bit calmer because you know she's going to get the job done."

Kapp is clear that she feels fortunate to be in the situation she is in - a fact brought home even more powerfully by the ongoing devastation of Covid-19, looting and violence in her home country.

"You worry a lot, I'm not going to lie," she said. "It's heartbreaking but I'm blessed to be able to be here and continue playing my sport that I love."

Kapp had her own battle with Covid before South Africa's T20I series with Pakistan in Durban in January and February. She was struck down for weeks with the illness, which prevented her from having a medical procedure for an ongoing heart condition, which forced her to retire hurt from a WBBL match last November.

With a hectic schedule leading up to, and beyond, next year's World Cup, Kapp will now have to continue managing the condition.

"I ended up not going for the [procedure] because I was really, really sick with Covid," Kapp said. "It's just something that I've learnt to play with. When it happens, it's not nice but usually I can get it under control.

"When they got me back to training [after Covid], first I had to start walking and just with walking my heart rate was 180, so I really struggled to get back. Throughout that whole Pakistan series I wasn't 100 percent, especially with the bowling, I really struggled and I was so tired. But I'm fine now."

With the rescheduled World Cup looming in New Zealand in February and March, Kapp believes South Africa, the No. 3-ranked ODI team behind Australia and defending champions England, have a golden opportunity.

"The squad we have now is probably the best we've ever had and the best we'll have for the next couple of years so if we don't do it now we'll never do it," she said. "Our team is especially good ODI team at the moment so with this ODI World Cup being pushed back it's a bit annoying but that's the ultimate goal for me."

And, even if that goal is achieved, Kapp has no intention of stopping there, with ambitions to play until she's 35.

"Now, for the first time, I know my skill batting and bowling wise," she said. "If I knew what I know now a few years ago, I'd be so much better. I still have a lot to give, hopefully."

Valkerie Baynes is a general editor at ESPNcricinfo