McLaren team principal Martin Whitmarsh believes Lewis Hamilton has already experienced regrets over his move to Mercedes.
Whitmarsh concedes he still does "not fully understand" why Hamilton opted to quit McLaren after 14 years and join Mercedes, who have won just one race in three years since their return to Formula One.
Whitmarsh can appreciate Hamilton's desire "to flee the nest" but remains disappointed by his decision, in particular as he feels it was made after a bad result in Singapore.
That was a race Hamilton should have won to firmly thrust himself back into the title picture, only to retire on lap 23 with a gearbox failure.
"It is always bad to make a decision in the aftermath of a bad race," Whitmarsh told the official F1 website.
"He was pretty sure he was going to win that race and it (the retirement) was a disappointment.
"I respect his decision, but I believe he would be better off with us; we are the stronger team and we intend to beat him next year."
Since Hamilton announced he was off to join Mercedes on a £45million three-year contract, the Brackley-based outfit have failed to score a single point.
McLaren have hardly set the world on fire either, although Hamilton should have won in Abu Dhabi on Sunday only to suffer another mechanical issue while leading from pole position.
Asked whether Hamilton already regretted his decision, Whitmarsh added: "I think he has on occasions, yes.
"Probably, when you make a decision you have to tell yourself that the decision is made so you have to look forward.
"You say 'Okay, that it is in the past', so you don't spend too much time thinking about why. You just look forward and make the best out of the new situation.
"You have to justify your decision. He is not going to say 'Hey, they offered me more money'.
"He is also not going to say he's made an awful mistake. I hope he thinks today he's made an awful mistake and I hope he thinks that next year.
"He's made that decision and he has to live with that decision."
Despite such comments, Whitmarsh knows the end of the final race in Brazil in just over a fortnight's time will be highly emotional.
"Right now we still want to win races. We are motivated by that and our conversation circles around that," he added.
"Maybe he is completely dispassionate about it, but my guess is we both will have very emotional moments in Brazil.
"I have known him since he was 11 and worked with him since his teens and I know we will both be very emotional after Brazil.
"We have had one or two emotional moments since the decision was taken and I believe, but you must ask him, that we have a very good relationship."