Nico Rosberg turned down a one-off opportunity to race for Audi in the German DTM series as a guest driver.
Rosberg retired from racing after his championship winning 2016 season, but the former driver remains involved in motorsport through his endeavors as a team owner in karting and as a minor investor in the FIA Formula E series.
The 33-year-old told Motorsport.com that he had been personally approached by Audi's Dieter Gass, but dismissed the chance to race the manufacturer's RS5 DTM contender.
"Dieter Gass from Audi just asked me if I wouldn't like to take part in a race as a guest drive, but I refused. I won't do that," said Rosberg.
"Just for fun, yes, but I don't even manage [myself] physically anymore. In my Formula 1 time I had to train so much for my arms and hands. Today it doesn't look that good."
The DTM allows for manufacturers to call upon guest-drivers to make a one-off appearance, and indeed series boss Gerhard Berger hopes to one day attract the likes of a big name, such as Lewis Hamilton or Sebastian Vettel.
That's an unlikely prospect however, according to Rosberg, at least while they remain in F1.
"I don't think that's possible," said the German. "They have so much to do, they have to focus on it. They can't start in the DTM now."
Rosberg believes that Formula E represents a better source of potential guest talent for the DTM given the number of drivers in the all-electric series that are contracted to manufacturers racing in the German championship.