Kevin Magnussen says he would not have "much interest" in returning to Haas for a one-off race with the US outfit as a substitute.
Haas boss Guenther Steiner recently suggested that he could call upon Magnussen or former teammate Romain Grosjean should the team find itself in need of a substitute for one of its drivers in 2021.
But Magnussen - who currently races for Chip Ganassi Racing in the IMSA WeatherTech Sportscar Championship and who will undertake a season in the WEC with Peugeot in 2022 - doubts he would respond favourably to a call-up from his former boss, even if he was available to do so in the future.
"Gunther is a good friend, as are many people in the Haas F1 team, but any talk about racing, like a one-off race, I don't have much interest in that," admitted the Dane.
"I like to be fully focused on what I am doing and I miss winning. I've done seven years of F1, [so] doing one more race I don't think is that interesting."
Magnussen sees little chance of him ever reviving his career in F1.
"If Mercedes came and asked me if I wanted to drive, I think everyone would look at that very seriously," he said. "I have given F1 a very fair shot; I think I have done my best to try to be successful.
"I've done it and feel like I'm ready to go and win some stuff again – that's really where I'm at."
As a front-runner with CGR's Cadillac team, Magnussen is well placed to stand on the top of podium this season in the US.
But the Dane's endeavor into the World Endurance Championship next year with Peugeot, which he has described as "the perfect step for me" will also offer the 28-year-old some exciting prospects.
"I am very much looking forward to start preparing for this journey," he said after Monday's announcement.
"The success has had at Le Mans and many other forms of motorsport means expectations are very high."