The 24-year-old Californian competed in five races with the then-Marussia team last year, but missed out on securing a race seat for the forthcoming season as the squad opted to sign rookies Pascal Wehrlein and Rio Haryanto.
Rossi subsequently went on to secure a deal to race in IndyCar in 2016, but will now perform an F1 role simultaneously.
“I’ve invested most of my career in F1 and I’m not one to kick my heels and wait for things to happen, so this is my way of staying sharp and prepared,” said Rossi, who will attend 11 Grands Prix this season, starting with the Russian Grand Prix in May.
“It was disappointing to miss out on a race seat with Manor Racing this year; everyone knows I pushed and worked hard for it. As official reserve driver though, I have a very complimentary dual program at the highest level of motorsport. IndyCar is the premier category of open wheel racing in North America and extremely competitive. I also have the privilege of racing with a championship winning team, Andretti Autosport.
“I’m confident this experience will add to my role as a very important cog in an F1 team’s wheel. My schedule this year is demanding, but no more than a full time F1 schedule. I will attend 11 Grands Prix, only five of which take place during the IndyCar season, and I am certainly used to the travel demands of the F1 calendar. It’s great to be back with a team I know and with whom I share a mutual respect and passion for the sport we love.”
Manor racing director Dave Ryan said that the team were fortunate to have someone of Rossi’s calibre in the reserve driver role: “We need a safe pair of hands for the role, which always carries the potential to have to step up to race, but also someone who can really contribute to the development of the car,” he said.
“For Alex, F1 is still unfinished business. He did a great job when he drove for us in five of last season’s races and he’s a highly rated and valuable part of our line-up. He does have one heck of a schedule ahead of him and it’s a commitment that only the most disciplined of drivers would be able to manage. We’re confident he’s the man for the job.”
According to Manor, Rossi will work with the team’s engineers and drivers to help develop the Mercedes-powered MRT05, contribute to team and partner marketing activities, and be available to deputise should he be required to compete at short notice.