Mercedes has revealed that Valtteri Bottas was riding on fumes when it comes to his tyres in Spain last weekend, as the team revealed that he "had no rubber".
Bottas eventually finished second, completing a Mercedes one-two, but he was close to completely losing his tyres. James Vowles, Mercedes' chief strategist revealed during the latest episode of Pure Pitwall.
"If the race had been a lap or two longer, we could have been in big, big trouble," he said in the video.
"It's fair to say that it was extremely marginal."
Bottas came in in the 19th lap for a fresh set of medium tyres, which meant that he had to do a second stint of 47 laps. The team decided not to pit during the Virtual Safety Car, which Vettel did do.
"We concluded based on all the evidence that we had is there was as strong possibility of Vettel [stopping]," said Vowles.
"It's extremely unlikely that anything else would have happened if we took it [a second stop].
"The last few laps of the race for Valtteri were very, very tense.
"We knew that the front left tyre would be very much down to zero rubber remaining."