Mercedes feared Lewis Hamilton could retire from the Mexican Grand Prix after his first lap error which damaged his tyres.
Hamilton was leading at the start of the race but locked up heavily approaching Turn 1 and took to the grass, skipping Turn 2 before rejoining the track. With the race then coming under the control of the safety car due to Pascal Wehrlein's retirement, Mercedes had time to analyse the situation and opted not to pit Hamilton.
Toto Wolff says the decision was taken in order to give Hamilton a chance of winning the race to aid his championship hopes, but admits it meant risking a retirement which could have handed Nico Rosberg the title.
"With all the bad luck Lewis has had throughout the season, he got some of that back, some of the good luck back, because he badly flat-spotted the tyre," Wolff said. "The vibration matrix was scary from the beginning. We had quite a conversation on the radio about whether we should pit him for safety reasons.
"In any other race we would have pitted him and lost the race. We kept him out there in order to not throw away the championship for him. Every single lap, every single straight, we monitored the vibrations.
"Our team did a fantastic job in keeping that under control and then we pitted him a bit earlier because the vibration matrix was going sky high and a suspension failure could have easily happened."
And Wolff says Hamilton had to get to lap 17 otherwise he was likely to lose the lead he built up in the first stint.
"That was the earliest we could have pitted him. Everything else would have destroyed the race. But honestly it was not a comfortable situation we found ourselves in there to make that call, weighing up the championship versus a failure of the suspension."
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