Valtteri Bottas considered not pitting for a second time such was his concern at stacking during the Chinese Grand Prix.

Plans for a one-stop race quickly changed in Shanghai after Max Verstappen changed back to soft tyres for an attempted charge at the two Ferraris.

Mercedes immediately responded by pitting both Lewis Hamilton and Bottas on the same lap, with the Finn issuing the message 'don't cost me any time' over the radio.

"I was very concerned," Bottas was quoted by F1i.com. "You know you're going to lose time being the car behind, but it was due to the start that I was in that position.

"I was questioning the team – if I could stop later or carry on without stopping – but there was too big a risk in terms of tyre life if we can make it or not."

It wasn't just the fear of a bad pit-stop though, as Bottas also pondered the chance to try and beat his teammate to victory.

"I was questioning because if I could do something different, other than stopping behind Lewis, that was going to be my only chance to win the race," he continued.

"I knew if we were coming in, that's going to be pretty much it unless something crazy happens.”

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As it was, the time loss was minimal and Bottas quickly repassed Charles Leclerc for second place.

And Mercedes boss Toto Wolff explained why he took great pleasure in the successful double stop.

“The double-stack was particularly a proud moment because we had everything to lose in P1 and P2 and we were thinking losing the position if we were to pit one of the two earlier and stacking functioned brilliantly,” he told Sky Sports.

“It was an interesting situation because it was clear that Valtteri in that situation was under pressure from Sebastian. So if Sebastian would have stopped, he would have undercut Valtteri.

"But if we would have stopped Valtteri [first], he would have undercut Lewis. So we didn’t want to interfere with the order, so that’s why we decided to stack.

“We knew that we were just about to have the gap to stack them properly. We gave the commitment to Valtteri that we wouldn’t lose any time, and it was really impressive how the guys did it.

“It was the choreography for everybody who understands Formula 1 was really impressive. It came so far that even [Daimler CEO] Dieter Zetsche called all the mechanics together and said he hadn’t seen anything like this before, and congratulations.”