Jenson Button has warned soon-to-be teammate Kevin Magnussen that there will be no escaping pressure in his first season with McLaren.
The 21-year-old Dane will replace Sergio Perez, who has been axed after just one season behind the wheel.
"It's one of those positions where it could light up your career or put an end to your career very early if things don't go well," Reuters quotes Button as saying.
"It's a massive risk to be put in the deep end, if you like, with a team that should be fighting for a title. But if a driver is willing to take that risk, he has a lot of confidence in himself and his ability.
"It could go one way or another and I hope it goes the positive way."
Magnussen, who was a part of McLaren's young driver programme, won the Danish Formula Ford in 2008, as well as this year's Formula Renault 3.5 Series.