Lewis Hamilton's future at Mercedes has been thrown into fresh doubt after his boss Toto Wolff revealed he could step back from Formula One.
Hamilton's contract is up for renewal in five months, and the world champion has said on the record his plans hinge on team principal Wolff's movements.
Like Hamilton, Wolff, who has presided over Mercedes' unrivalled and remarkable six consecutive driver and team Championships, is out of contract at the end of the campaign.
The Austrian (47) said discussions over a new deal with Ola Kallenius, chairman of Mercedes' parent company Daimler, are ongoing and positive.
Speaking ahead of tomorrow's Spanish Grand Prix, Wolff said: "Lewis staying is the best thing he can do and what he wants to do. He has the possibility of achieving great success, winning more races and hopefully Championships, and it's flattering that he says his future is dependent on what I do. But he doesn't need me. He has a great team there that will always support him.
"I don't want to spin that I am leaving, that is not the case. I am in a moment of reflection where F1 is heading to, what is happening with Covid and for personal reasons, too.
"My wife Susie is in a good place running a Formula E team but that means she is away a lot. I've been to God knows how many F1 races, something like 120 in the last eight years.
"I really have enjoyed many years in Formula One in my role as team principal. I am happy that my relationship with Ola is as good as it can be and we speak almost every day, and there are many factors that make me want to stay in Formula One.
"On the other side, it takes its toll, and this plays into my consideration. It doesn't mean I will not be around as a team principal or in another role but just I am thinking about it. I never want to be in a situation where you go from very good to good."
Hamilton, who holds a 30-point Championship lead over Red Bull's Max Verstappen in his bid for a record-equalling seventh World Championship, looks likely to extend his stay with Mercedes. Indeed, he said on the eve of last month's British Grand Prix that he could race on for another three years.
But Wolff's comments might provide the Briton, who said he is yet to open formal discussions with Mercedes over a new deal, with food for thought.
Hamilton clocked the fastest time in second practice for this weekend's Spanish Grand Prix.
Mercedes team-mate Valtteri Bottas beat Hamilton to top spot in the first running at Barcelona's Circuit de Catalunya yesterday morning.
But Hamilton ended the final track action of the day 0.287 seconds faster than the Finn.
While Verstappen curtailed Mercedes' winning streak with a fine victory at the 70th Anniversary Grand Prix at Silverstone last weekend, the Dutchman finished a distant third.
He was eight tenths behind Hamilton, with Renault's Daniel Ricciardo the only other driver to be within one second.
Romain Grosjean finished an impressive fifth for Haas ahead of the Ferrari of Charles Leclerc in sixth.