Mercedes considered halting Nico Rosberg in his chase of the Canadian Grand Prix victory due to brake issues which could have ended his race.
The Circuit Gilles Villeneuve is one of the heaviest on brakes on the F1 calendar, with Lewis Hamilton retiring from the 2014 race due to a failure of his rear-brakes.
Toto Wolff admitted that the German marque was concerned that the same problems could reoccur on Sunday which led to a fine balance in race management.
“It is a circuit which is very heavy on the brakes, and it is a fine line between not interfering in the racing between the two drivers and on the other side trying to make sure the car survives,” said Wolff.
“At a certain stage we had more than a 30-second gap to [Valtteri] Bottas, but we had high brake temperatures and were a bit marginal on fuel [so we had to back off].”
Similarly to Hamilton in 2014, Rosberg suffered from high brake temperatures chasing down the leader, leading to calls for the German to lift and coast to help cool them, or face a possible failure.
“After the first third of the race Nico’s brakes were in danger – very, very high temperatures,” added Wolff.
“There was a very clear message we passed onto him to look after them.
“For us, the brakes were a bigger problem than the fuel.”