Most Formula E teams have an elected reserve or development driver that can step in when either of their full-time drivers has to miss a round - particularly pressing at the moment with the ongoing pandemic and the elevated risk of falling ill. There's more to the role than a substitute appearance now and then, though.
Mercedes-EQ has DTM legend Gary Paffet and former Formula 1 driver Esteban Gutierrez on its books; Adam Carroll has driven for Jaguar Racing in Formula E and is now reserve at NIO 333; and former NIO racer Tom Dillman and Japanese Formula 3 champion Sacha Fenestraz are at Jaguar while James Rossiter is DS TECHEETAH's reserve driver as well as its Sporting Director.
ROKiT Venturi Racing signed Jake Hughes this year in place of the promoted Norman Nato after the Frenchman moved from his role as reserve to a race seat for Season 7. Nissan e.dams haven't announced a formal reserve but Jann Mardenborough - its simulator driver - and Mitsunori Takaboshi would be good bets having turned out for the team at the Marrakesh Rookie Test in Season 6.
Quick Nick!
Mahindra Racing can rely on Nick Heidfeld. The ultra-experienced German - who made 44 starts and sealed eight podiums in his Formula E career and started 183 Formula 1 Grands Prix - would step into the breach should Alex Lynn or Alexander Sims be unable to race, and he's a vital cog in the Indian outfit's machine as an advisor. No doubt if called upon, he'd be a safe pair of hands.
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"I've been around motorsport a long time," said the 44-year-old. "Over the years you realise how important experience is. At events, I keep a close eye on things and feedback to Dilbagh (Gill, Team Principal) where I think we might be able to improve. Ideally, I'd never be needed if everything goes smoothly, but that's never the case in Formula E!
"With COVID, it's more likely someone misses out and it's never easy to just jump in. Formula E is quite complicated, especially with energy management. There's a lot of data on the dashboard, a lot of different strategies to follow and we replicate that in the simulator - but even that's difficult with travel at the moment.
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"I know what the basics are, they haven't changed. I'm prepared as I can be but there isn't much testing and the races are over just one day. That's what makes it challenging and it's different to everything I did before. I like to have something new and different as a challenge."
The 'Iron Maiden'
Porsche has Simona de Silvestro to call upon. The experience Swiss racer drove karts from the moment she could reach the pedals aged seven, and years of hard work and sacrifice paved the way for de Silvestro to live out her racing dream.
After initial single-seater successes in Europe, she was drawn to the USA at 17 years old. Through Formula BMW and Formula Toyota Atlantic she ended up in the IndyCar Series.
She made a big impression, and was crowned ‘Rookie of the Year’ at the legendary Indianpolis 500 in 2010. De Silvestro earned even greater recognition among drivers and fans a year later when, the day after a serious accident in the practice session, despite burns on both hands, she got into the car and qualified at Indianapolis - earning her that "Iron Maiden" nickname.
In Formula E, de Silvestro's made 12 appearances for the Andretti outfit in the 2014-15 London finale with a streak of 10 starts in 2015-16. Since then, she's dovetailed test driver roles for Venturi with GT racing and now represents TAG Heuer Porsche as its official reserve driver.
"I'm there to jump in and drive if Pascal (Wehrlein) or Andre (Lotterer) can't," she says. "I'm with the team doing the track walk, all the meetings and listening and learning.
"The tricky thing in Formula E is the lack of testing. Everything is done in the simulator. Testing stops once the season starts. Our sims are pretty good, pretty advanced, so you get to know the tracks and energy management especially is difficult. It's so different to any other racing series.
"Alongside this I'm racing for Porsche in the GT Masters in Germany which is exciting and completely different again. I also did the Indy 500 again this year, which was very exciting after six years out - that's such an historic event.
"When you're reserve you always come with the hope that you have to jump in, but we all really get along and we all work really well together. If in the case it happens, I'd be really happy to drive and you never know, but I'd be ready if it happens."