Pascal Wehrlein has reportedly admitted that he is heading to Sauber for 2017.
It is yet another strong sign that Valtteri Bottas's move from Williams to Mercedes to replace new world champion Nico Rosberg is complete.
Wehrlein was earlier a strong contender to replace the retiring Rosberg, but recent reports suggested a deal for the Mercedes junior to instead move from embattled Manor to the Ferrari-powered Sauber team has been agreed.
"Sauber is clearly improving now," Roger Benoit, a veteran F1 journalist, quoted German Wehrlein as saying.
"I'm delighted to be a part of this great team," Wehrlein added, according to Swiss newspaper Blick.
The 22-year-old picked up Manor's sole point of the 2016 championship.
