and are a “potentially explosive combination”, according to Ferrari’s former technical director .

Vettel, 32, disobeyed orders to let 21-year-old Leclerc pass him to lead Sunday’s Russian Grand Prix.

The German four-time world champion is fifth in the Formula 1 standings, 21 points behind the Monegasque in third.

“It’s a potentially explosive combination and needs careful handling,” said Brawn.

“Ferrari has made a lot of progress but it still has to deal with the balance between its drivers.”

Since the in June, Leclerc has out-qualified Vettel nine times in a row, at an average advantage of more than 0.4 seconds a lap. He also has six poles and two wins this season to Vettel’s one.

Ferrari wanted to fashion a one-two finish in and achieve a fourth straight race win, but instead the one-two went to , with Le Hamilton taking the chequered flag followed by Finnish team-mate .

The Briton now leads Bottas by 73 points at the top of the world title standings.

Brawn was with Ferrari during their years of dominance when won five successive world titles between 2000 and 2004. Now he is backing current team principal to resolve any problems within the team.

“The honour and obligation falls to him [Binotto] to make sure that the mechanism that drives what can be a healthy rivalry runs smoothly,” he said.