Former Formula 1 world champion Mika Hakkinen says that Ferrari must find a way to solve the mounting tension within the team if it is to finally beat the rival Mercedes squad in 2020.
The last two races have seen growing friction between drivers Charles Leclerc and Sebastian Vettel won in Singapore after the team used the 'undercut' pit stop strategy to put him ahead of Leclerc.
In Sochi Vettel appeared to be reluctant to undertake a previously agreed swap between the two cars after a tow from Leclerc helped him take the lead at the start of the race. However the disagreement became irrelevant when Vettel suffered a subsequent technical failure on his SF90.
But writing in his regular column for Unibet, Hakkinen said that if the situation was not tackled by team principal Mattia Binotto then there was a risk it could ruin their hopes of challenging Mercedes for the 2020 driver and team titles.
"After starting from pole position - his fourth pole in a row - Charles Leclerc had every right to expect a great result on Sunday," Hakkinen said. "But it all went wrong when he agreed to give Sebastian a tow down the long straight to the first proper corner, Turn 2. .
"In agreeing to give Sebastian the lead it opened up the opportunity for him to control the race, which he did perfectly.
"There is tension in Ferrari between the drivers, and Charles is learning some tough lessons," Hakkinen continued. "Including the fact that Sebastian did not win four world championships by being a pushover.
"Compared to Mercedes, Ferrari does not yet have the perfect teamwork between the drivers, and they need to do that if they are going to win consistently. Fighting inside a team never works.
"The interteam battle at Ferrari may continue, but if they can resolve that and find a way to work together then Mercedes Benz will have a real battle on its hands. Not just in Japan, but for the rest of the season [and into 2020]."
Hakkinen also praised a strong performance from McLaren drivers Carlos Sainz and Lando Norris in Sochi, which give the team a boost over rivals Renault who currently supply their power units.
McLaren made the surprise announcement in Russia that they were returning to the Mercedes fold in 2021, with Hakkinen admitting he was entertained by the fall-out in the media.
"The McLaren Mercedes news has sparked a range of beautiful theories and conspiracies both in the immediate and long term futures of the sport," the Finn commented.
"McLaren’s determination to join Mercedes, Ferrari and Red Bull Racing in battling for victories is important, both for them and for Formula 1," he added.
"If even a few of them come to pass, we’ve got a hell of an 18 months ahead of us!"