Valtteri Bottas was 0.670 seconds off the pace-setting Ferrari of Sebastian Vettel in FP2 at the Russian track on Friday afternoon, while teammate Lewis Hamilton was a further 0.039s off.

Both drivers struggled to get a good lap in, and both experienced off-track excursions.

"You could see you needed a couple of laps to put the tyre in the window, and you needed to have clean laps, then it's easier," said Wolff.

"And if you haven't got the clean laps, you won't be putting it in the right spot.

"The wider window is, and the easier you put the car into the tyre window, the faster you go. The more narrow it is, the more difficult it is to hit the window, and this is what we are seeing at the moment.

"The Ferrari seems to be a car that is pretty robust in a wider window temperature than ours, and it doesn't matter whether it's Bahrain, where it's very hot, or Sochi where it's cold. It's just a very good car."

Wolff acknowledged that his drivers had struggled to get a representative laptime.

"It was a difficult day, a lot to analyse and a lot to learn," said Wolff. "Cars and teams being offset in pace, some quicker than expected, some slower than expected.

"It's about just looking at all the data, and putting the car in the right window."

Despite the frustration, Wolff says the team has an idea of what to improve for Saturday, and thus the situation does not compare with the Singapore GP of two years ago, when it struggled all weekend.

"There's a pretty good indication what's happening, and what they have been doing, so it's all relaxed until now," he added. "In Singapore 2015 we were the only team out of position, and we just couldn't make the tyre work.

"What you can see is there is one team that is extremely fast today, for whatever reasons. There are pretty good clues."