Stoffel Vandoorne says his main focus will be on Formula E in 2020.
The former McLaren driver may now be a frontrunner in the electric series, but he has just been signed up as Mercedes' new F1 reserve.
"It's very nice to go a step up within in the Mercedes family," the Belgian driver told RTBF.
"I was already involved in a lot of the simulator work, but now it will be a very busy year for me.
"I will be at all the grands prix unless they overlap with a race in Formula E. That (Formula E) is my priority, and the Formula 1 team knows that too."
Indeed, Vandoorne says he is not eyeing a full return to Formula 1 "at any cost".
"And if I have to step in as a spare driver, then there would have to be a serious incident for Lewis Hamilton or Valtteri Botas and of course I do not hope for that.
"But if I have to, I am ready," said the works Mercedes driver in Formula E.
Overall, however, 27-year-old Vandoorne says he is happy in Formula E.
"I had a very good start to the season and I think I can have a very bright future in Formula E. I can show good results here, and that is the most important thing now," he said.
