2022 could be Lewis Hamilton's final season in Formula 1.
That is the suspicion of a couple of renowned experts - including a top official of the team whose driver beat the seven time world champion to the 2021 title.
"Hamilton knows the opponent Max (Verstappen) has grown into," Dr Helmut Marko told Sport1.
"He knows how much effort he now has to put in, how much energy it takes to beat him. You don't want to do that to yourself forever," he said.
"The question of how his new young teammate George Russell behaves towards him will also be decisive," Marko thinks.
Former F1 driver Ralf Schumacher agrees that how Hamilton handles the challenge of George Russell this year is "one of the most exciting questions".
"The next generation of Mercedes is now driving alongside Lewis," said the German. "Because let's not kid ourselves - Mercedes has to think about the future and that's called George Russell.
"It will be interesting to see how everyone involved deals with this situation."
Ralf thinks even Hamilton's contract for 2023 won't necessarily stop him from quitting.
"If a driver wants to end his career, there is usually a clause that can dissolve the contract," he said. "That was the case with Nico Rosberg at the end of 2016 and also with me when I ended my DTM career before the race first of 2013."
Schumacher says Hamilton would be missed by Formula 1, and especially the American market which was "woken from its slumber" by the 37-year-old.
"Of course he polarises, of course you can argue about his fashion taste, but one thing is certain - he is the greatest ambassador of the sport and therefore so immensely valuable," said Ralf.
He thinks winning a record eighth title this year, beating his own brother Michael, would be the perfect time for Hamilton to quit on top.
"Lewis is getting on in years - you just don't get any younger," the 46-year-old smiled.
"I can't speak for him, but saying goodbye at the top would be a logical argument for me. For me, at some point I was no longer willing to put in all the effort to stay at the front."