Alexander Rossi says the chance to make his Formula 1 debut with Manor Marussia at the Singapore Grand Prix is 'surreal'.
Rossi has had reserve driver stints with both Caterham and Marussia and twice came close to making his debut with the Anglo-Russian team in 2014, prior to its demise.
Rossi, who has been racing in GP2 this year, says that he now has an opportunity to prove his worth across the remainder of 2015.
"The big thing that I've been missing for the last three years in my Formula 1 career is actually racing," he explained.
"We have been close a few times, but it's very surreal now that it is about to happen.
"This is a major step in really firmly putting myself on the Formula 1 map and the radar, so I'm just focusing on doing a good job in these next five races and showing that I am capable of being in Formula 1 and doing a good job."
Rossi added that his 2016 plans remain uncertain, but that his stint with Manor Marussia will enable him to be seen.
"I'm going to try and prove that I am more than capable of racing in Formula 1 and that I have all of the necessary boxes ticked," he said.
"The best way to do that is on track and being the only American with a super licence and now a race start is some stuff I have in my corner for sure. But whether it leads anything has yet to be seen."