Honda MotoGP boss Alberto Puig says Yamaha rider Valentino Rossi is "having a hard time accepting" that he is no longer the premier class' benchmark rider.
Rossi has established himself as a MotoGP legend by winning seven titles, but has been unable to add to his championship tally since 2009.
He developed a rivalry with Honda's Marc Marquez - who this year secured a dominant fifth MotoGP title from six attempts - at his most recent title near-miss in 2015, when Rossi came up five points short of an eighth crown.
The relationship between the pair has remained tense and Puig, who took up the team boss role at Honda at the start of the year, suggested Rossi was the culprit in the rift.
"Valentino has been a terrific rider," Puig told Spanish daily La Vanguardia. "He has all of my respect.
"At his age , he still has the desire, the talent to go fast and he doesn't accept not being able to win.
"But he's having a hard time accepting that his moment is over. Sometimes the methods he uses are not the right ones.
"At no time have I seen Marquez out of line, doing anything malicious towards Rossi. It was always race incidents.
"I respect Rossi, but in life everything has its moment. And like it or not, Marc is number one [now]."
Rossi was extremely critical of Marquez earlier this year after a collision with the Spaniard in Argentina left him on the floor.
Marquez tried to apologise to Rossi after that race but was aggressively turned away by the Italian's right-hand man Uccio Salucci, while Rossi later turned down Marquez's offer of a handshake during a Misano press conference.
"Marquez doesn't care at all about the tide of opinions that is being generated from Vale's environment," Puig continued.
"On the contrary, we have sensed weakness in their actions."
Puig, who was instrumental in signing another of Rossi's rivals, Jorge Lorenzo, for 2019, described 25-year-old Marquez as being "quite close" to a perfect rider.
"Marc doesn't act like a superstar, he doesn't pretend to be someone he isn't," Puig said.
"He has the humility and curiosity to listen, to learn and to have respect. When he gets on the bike, he is a real killer, which is what he has to be. He's a machine programmed to go at full speed.
"Perfection doesn't exist, but he is quite close. Perfection is being the best, and he is. As to how much better he could be - given his age, he still has room for growth."