Sebastian Vettel and Charles Leclerc dropped out of the race after hitting each other - an immediate annoyance which highlights a major difficulty coming up for the team. Photo: Ricardo Moraes/Reuters

SAO PAULO  Drivers regularly push to the limit in the cut-throat world of Formula One but are expected to abide by one golden rule: don't hit your team-mate.

That means Ferrari pair Sebastian Vettel and Charles Leclerc can expect to be dragged into the office of team principal Mattia Binotto this week for a severe dressing down after taking each other out of Sunday's Brazilian Grand Prix.

"Of course we now need to sit down and decide together where the limits are to make sure we all push for the benefit of the team and make sure these things don't happen any more," Binotto told the media, displaying an outward calmness despite any inner anger being held.

With the drivers' and constructors' titles already settled, the Sao Paulo race was a magnificent free for all. Max Verstappen twice passed champion Lewis Hamilton to secure a brilliant win for Red Bull while Hamilton was penalized for hitting Alexander Albon with his Mercedes.

That cost Albon a first career podium in the other Red Bull and allowed Pierre Gasly - demoted to Toro Rosso midseason - to claim an unlikely second and Carlos Sainz to end a McLaren podium-drought of more than 2,000 days with third.

But the stand out piece of drama was the latest round of Vettel v Leclerc. Not only does it symbolize the increasing intensity of a long-bubbling internal rivalry but highlights the massive difficulty Ferrari will have in preparing for next season.

The Scuderia will definitely finish second behind Mercedes in the constructors' title so, as Binotto said, the "drivers were free to race today and they knew that."

But while saying the clash was a "small collision that had a big consequence," Binotto also acknowledged: "In truth, this sort of thing should never happen."

Late in the race Leclerc passed Vettel but going onto a long Interlagos straight had to immediately defend from his team-mate. Vettel, with DRS enabled, edged ahead again but cut inside early as Leclerc had left him no more than the absolute minimum space required to approach the next corner.

"It's a shame about the collision between us, especially for the team as a whole, given that both cars were in the points and considering how much work everyone puts in, both at the track and back in Maranello," said Vettel, who kept his own counsel regarding blame and future consequences.

Leclerc said it was a "real pity" to end a point-scoring weekend in such a fashion and will likely feel the safer of the pair about to be put on Binotto's carpet.

Not only is his claim to being right on the track slightly stronger, Binotto will be aware Vettel struck former Red Bull team-mate Mark Webber in similar circumstances in Turkey back in 2010.

And despite being in his debut season with Ferrari, and just second in F1, the 21-year-old Leclerc has outperformed the four-time world champion Vettel.

He has more wins (2-1), poles (7-2), fastest laps (4-2) and points (249-230) with only the number of podiums being tied at 9-9.

The 32-year-old Vettel has now had five seasons at Ferrari and, through a combination of team problems and his own errors, has not managed a consistent title challenge.

While the German started this season as the team's number one driver, the evidence shows he has been usurped.

"There will be time to judge. We will do that together," Binotto said. He was talking about the racing incident in Brazil. Vettel may fear, however, his words could also apply to 2020.