Suzuka: Lewis Hamilton believes Charles Leclerc has usurped four times world champion teammate Sebastian Vettel as Ferrari's favourite.
Tensions between the 21-year-old Monegasque and 32-year-old German flared in Russia two weeks ago when Vettel appeared to ignore a pre-race pact to hand back the lead to Leclerc after the start.
"It's an interesting dynamic they have there," Hamilton told reporters ahead of a Japanese Grand Prix that could crown his Mercedes team as constructors' champions for the sixth successive season.
"Seb was number one. Now, clearly not.
"From the energy, the outlook...(Ferrari are) trying to ramp Charles up," added the Briton, who leads team mate Valtteri Bottas by 73 points with five races to go and is also heading for a sixth title.
Ferrari have long had an obvious number one and two, with Eddie Irvine and Rubens Barrichello playing the supporting role to Michael Schumacher, who retired with seven championships.
Vettel, who joined the Italian team in 2015 hoping to emulate boyhood hero Schumacher, enjoyed the lead role until this season.
Leclerc, an ambitious youngster still in his first year at Ferrari and only his second in Formula One, has turned the tide his way.
The Monegasque handed Ferrari their first win of a difficult year in Belgium at the end of August and followed it a week later with the team's first home victory since 2010 at the Italian Grand Prix.
He has racked up four consecutive pole positions, the first Ferrari driver to do so since Schumacher, and outqualified Vettel for nine straight races.
Vettel won in Singapore and, as the Ferrari grew more to his liking, has begun showing the old fire and flashes that carried him to four successive titles from 2010-2013 with Red Bull.
Hamilton, who unsettled reigning double world champion Fernando Alonso when they were team mates at McLaren in the Briton's rookie year in 2007, said he knew what it was like to come in and rattle an established star.
"I do understand," said Hamilton. "When you arrive you want to have equal opportunity.
"But there are drivers that always wanted that number one status, it's easier for them. I like to earn that, start on an equal platform.
"If you already know you're number two, it's kind of defeatist."