Alexander Rossi will have double duties in 2016 as, alongside his IndyCar drive, he will also fill the role of Manor's reserve driver in Formula 1.
Failing to secure a race-seat with the Mercedes-powered team for this year's championship, Rossi turned to the IndyCar Series for a drive signing with Andretti Autosport.
However, alongside those commitments he will also remain in Formula 1 as Manor's reserve driver.
The team has announced that he will attend 11 grand prix weekends with the team, working with the engineers and drivers – Pascal Wehrlein and Rio Haryanto – to help develop the MRT05.
"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," the American said.
"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 Series 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."
Rossi's first grand prix weekend with Manor will be May's Russian GP.