Schumacher assumed this role with the intention of making a return to the grid in the following season. Although discussions with Alpine for his involvement in their endurance racing program have emerged, Mercedes team principal Toto Wolff has left the door open for Schumacher to continue as their reserve driver, even if he pursues an external project.
According to Heidfeld, to maintain his hopes of returning to Formula 1, Schumacher must not sever his ties with the series.
"He should try to keep one foot in Formula 1, even if it's just as a test driver," Heidfeld told F1-Insider.
"Back then, I was a test driver for Pirelli and a reserve driver for Mercedes. We can see it with Nico Hulkenberg as well.
"He was written off three times and now he's firmly back in the saddle. You always have to believe in yourself and the opportunity, never back down, and seek your chances. I hope and believe that Mick is doing that and has the right guidance."
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