It's possible that Sebastian Vettel will launch an audacious return to Formula 1, according to Red Bull's Dr Helmut Marko.
At the weekend, the newly-retired quadruple world champion demonstrated his title-winning 2011 Red Bull at the Nurburgring - and applauded the dominance of the team's current champion, Max Verstappen.
"One can only applaud," the 36-year-old German told Sportschau.
"The performance of the entire team, but especially that of Max, who does it so consistently every weekend, is great. It's a level showing how far away the competition is.
"You have to acknowledge that and take the position that it's great that we can watch."
Vettel, who last raced for Aston Martin, also admitted that he remains in contact with some members of the Red Bull team.
"There is still an exchange going on," he revealed. "The boys have a lot to do and do a lot of travelling, but I know them all. I'm in contact, occasionally on the phone.
"I'm still somewhat involved."
Marko, who brought both Vettel and Verstappen into F1, thinks it's possible the German will return.
"Sebastian isn't working on anything in particular at the moment and I'm not sure he knows what exactly he wants," he told Servus TV.
"However, I do not believe that the driving chapter is completely closed for him."
Austrian Marko, 80, ruled out pairing Vettel with Verstappen, and also played down the likelihood of an Alpha Tauri seat for him.
"The contracts we have will continue for a while," he said. "It would also not be an easy decision for him, because Formula 1 will continue to use fossil fuels.
"Motorsport is still about combustion engines and gasoline, so that would be difficult for him to reconcile. But if he sees things going in the right direction, I don't see why not."
