(CNN)They are the forgotten men of Formula One, consigned to live in the long shadows of the sport's global superstars.
Reserve drivers: The forgotten men of Formula One
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Like an understudy on the Broadway stage, reserve drivers must be ready to step into a lead role at a moment's notice while never sure if, and when, the wait will end.
It is a gamble between glory and obscurity.
"Normally nothing happens," Pascal Wehrlein, understudying for double world champion Lewis Hamilton and Nico Rosberg as reserve driver for world champions Mercedes, told CNN.
"If something happens to Nico or Lewis I'll be in the race car. It must be really bad luck if one of them couldn't drive but I'd step in."
The 20-year-old German arguably has the most coveted reserve role on the F1 grid with the fastest car in the world within touching distance.
Already racing for Mercedes in the German touring car championship, known as DTM, he was promoted to a role in F1 last season.
His apprenticeship as a reserve driver sees him travel to every grand prix where he joins Mercedes' star drivers in the team debriefs throughout the 2015 season.
"You take all the information you can," he explained. "The target this year is to learn everything: procedures, all they say about the car and getting confident with everyone within the team.
"You learn from watching the drivers but also talking to them. You have to learn everything about the car so that, if I jump in, I don't do so not knowing anything, not prepared."
Wehrlein said Hamilton and Rosberg had both offered him advice ahead of his first official duties for Mercedes testing in Abu Dhabi at the end of the 2014 season.
"Before Abu Dhabi in particular they were very good speaking about the car," said the German, who underlined his potential by closing the test as the fastest driver.
Opportunities for a young racer to show off his skills behind the wheel is, in reality, limited.
For F1's men in waiting, the motion platform car simulator, used by the majority of F1 teams to hone driving skills and car improvements, are the next best thing.
Before being announced as the team's official reserve driver, Wehrlein had already tested extensively for Mercedes, notching up 12,000 kilometers at the team's Brackley base.
Last year the 20-year-old calculates he did more than 30 days in the simulator - averaging a day or two a week clocking up the kilometers on the expensive piece of machinery.
Initially it helped him learn the various race tracks on the calendar, whereas this season it will be more to feed back to both drivers about the car.
But the role of reserve driver can act as a stepping stone to world domination. Double world champion Fernando Alonso carried out such a role before making the step up to a full race seat with Minardi and then Benetton.
Romain Grosjean was a one-time understudy to Alonso and then teammate Nelson Piquet Jr at the team that Benetton spawned into, Renault, and made the step up into a race seat following Piquet's acrimonious exit from the team in 2009.
For Grosjean, who is now firmly established as a driver with the team in its new guise of Lotus, there were difficulties in the role.
"As reserve driver, I didn't drive at all," the Frenchman recalled. "There was not even a simulator at Enstone [the team's headquarters].
"It was also hard to work with the drivers as they were thinking 'this driver wants to get your Friday' [a practice session] or your race seat, so it is a little hard to get on with the race drivers."
Lotus' position with reserve drivers has been changed and they now support a driver development programme, a path Grosjean took to his race seat.
"The way it worked with the junior drivers, and still does, is that they work closely with the team," he explained.
"So you get to know everyone at the factory, you see people in training, you get to know the wind tunnel.
"You see things, watch from the outside and try to get it right when you get your chance. And by the time you get your chance, you're ready and you can fit in more easily."
The role of reserve was also a vital part of the learning curve for David Coulthard, who would go on to win 13 grands prix during a glittering career with Williams, McLaren and Red Bull.
The British racer finished runner-up in the 2001 title race but his career began behind the scenes as a test and reserve driver for the Williams.
There, he learned from a trio of world champions in Nigel Mansell, Alain Prost and Ayrton Senna, before making the jump to a race seat following the Brazilian's fatal crash at the San Marino Grand Prix.
"You just soak absolutely everything up," said Coulthard, who said it was important for reserves to act like a sponge.
"I was so lucky to test for three greats in Senna, Prost and Mansell. It let me take my talent to a higher level by seeing them in a different way that I couldn't see them when racing.
For the Scot, each of the trio of champions gave him something to log in his mind as he set about on his own quest for a race seat.
"Mansell was a lot more detailed with his set-up than people gave him credit for," said Coulthard. "He was very driven by lap time. He wanted to set a quick lap time in the morning practice and then go off to the golf course.
"Prost was so different. Three or four laps into a test, he'd be out of the car, drinking an espresso, biting his nails, talking about it. It was like he was really minimizing his time in car to get the most from it when in there.
"And then there was Senna, who was a mix of them all - he could deliver the speed, he could get out there and do the hard work. His work ethic was very impressive."
The position of reserve driver can be filled by experienced hands like Pedro de la Rosa, who spent seven years in the role for McLaren, to youngsters like Wehrlein.
And there are 2014 racers who have been forced back to a reserve driver's role for next season, namely former Sauber racer Esteban Gutierrez at Ferrari and Kevin Magnussen, who stepped down out McLaren to make way for Alonso.
"Kevin and Esteban will benefit greatly from a year out watching these guys," argued Coulthard.
"If say Magnussen can analyze the hell out of Jenson Button and Alonso all season long he can only be quicker when he's back in a race seat.
"I think a stint as a reserve driver is very important. When I first drove an F1 car at 19, that was fine, quicker than anything before but enough for me to realize it wasn't a rocket ship, this was achievable.
"In the reserve driver role it's more about life experience, business decisions, being tuned in and learning to be a bit more worldly."
Watching and waiting may be essential attributes for a reserve driver but, even from the sidelines of a garage, their racing instincts still burn.
"You never hope for this," revealed Wehrlein. "You want to get into the car at the beginning of the season and do every race, not just one race.
"To drive races is the dream."
Coulthard, Grosjean and Wehrlein were competing at the Race Of Champions. To find out more, visit www.raceofchampions.com.