Mercedes explains 'painful' Hamilton VSC blunder in Austrian GP

The team admitted to a wrong strategy call after Valtteri Bottas retired from the race and triggered the VSC, which meant all the frontrunners except leader Hamilton made pit stops.

Hamilton lost out massively but later retired anyway with a loss of fuel pressure that resulted in Mercedes's first double retirement since the four-time world champion's clash with Nico Rosberg at Barcelona in 2016.

"What I think happened was we were running one and two and controlling the race, and suddenly you see your second car stopping," said team boss Toto Wolff.

"The VSC came out, we had half a lap to react, and we didn't. Fact. This is where we lost the race.

"At that stage of the race with the VSC, pitting is probably 80% the thing you need to do.

"With one car out there against two others, the thinking process that happened was, 'what would happen if the others pitted a car?'

"We would come out behind Kimi [Raikkonen] because they would leave Kimi out and behind Max [Verstappen]. What would that mean for the race?

"That whole thinking loop I wouldn't say distracted us, but we spent too much time on that.

"For me, [this is] the most painful day in my years at Mercedes, worse than Barcelona.

"I had plenty of people coming to see me before the start and saying, 'This was going to be a walk in the park, one-two, you have the quickest car.'

"This is exactly how motor racing can go. It can be very cruel and we had all the cruelty go against us today."

Wolff admitted that Mercedes was surprised by the tyre issues that surfaced in the race, with conditions were much warmer than in practice.

"The only ones who didn't have the tyre problems were the Ferraris, but all others suffered from heavy blistering and that was definitely not something that we expected," said Wolff.

"It was 10 degrees hotter than planned, but I guess it was due to the fact that everyone who suffered from the blistering was attacking.

"We were going flat out, and going flat out means you are overheating the surface of the tyre, and that causes the blistering."

Wolff also stressed that neither of the retirements were related to Mercedes's recent power unit upgrades.

"It's nothing to do with the reliability of the engine as far as we can see," he said.

"We had a hydraulic leak that was [on] the steering of Valtteri and we had a drop in fuel pressure on Lewis's car, which was linked to the fuel system.

"This is our current understanding. So, no regrets on introducing the engine."