However, Schumacher told Sky Germany of his desire to keep fighting for a seat on next year's grid: "I said it before that I won't give up.
"There are still two open seats. We have to keep working on it, keep going. In the end, it is also understandable that they chose this route.
"He [Doohan] was part of their junior program and that was probably the link. For us it is still about pushing, keep working and hopefully with a good result at the end of the year.
Schumacher's Mercedes reserve role was not enough to earn him a full-time seat with the Brackley-based outfit, given that the team announced academy driver Kimi Antonelli as part of their 2025 line-up after his spectacular crash at Monza last weekend.
There are now just two seats currently open for 2025, with Kick Sauber and Visa Cash App RB both yet to confirm their second driver for next season.
For Schumacher, surely the dream now is to sign with Sauber who, under the watchful eye of Mattia Binotto, will become Audi in 2026- meaning he could potentially partner Hulkenberg and be part of an ideal partnership of two German drivers for one of the most iconic German brands in motorsport.