Pascal Wehrlein could not hide his disappointment after it emerged that Manor teammate Esteban Ocon is moving up to Force India for 2017.
Both backed by Mercedes, German Wehrlein is the more experienced of the pair but he has been overlooked for the more competitive seat.
"Toto [Wolff] called me," he said. "He said Force India chose Esteban and I will have to understand why that is or what I can improve from my side."
It is now almost certain that Wehrlein will stay with Manor for a second season, perhaps to be joined by the Haas refugee Esteban Gutierrez.
Wehrlein said in Brazil: "It is not the end of the world, it is a missed opportunity but I am happy to stay here and try to make another step next year."
Asked how he is coping with the news that the younger and less experienced Frenchman Ocon got the Force India drive ahead of him, Wehrlein said: "I have to deal with it.
"I can say something bad now but that will not help me. It has been coming for days and yesterday I got the confirmation and all I can do is wish Esteban all the best.
"I will now continue to show on the track what I have in me - this is a small step back but no more."
The 2016 calendar concludes on November 27 with the Abu Dhabi Grand Prix.