Singapore GP: Sebastian Vettel had thought Mercedes was sandbagging

Mercedes was outpaced by Ferrari and Red Bull in second practice on Friday and again on Saturday morning, and the world champion team was adamant it was showing its true pace.

That proved to be the case when Lewis Hamilton and Nico Rosberg could only qualify on the third row of the grid, and it came as a surprise to front row starters Vettel and Daniel Ricciardo.

"It's a surprise - I thought they were sandbagging yesterday, also this morning," said Vettel of Mercedes.

"There is no doubt they have the strongest package this year - they must have some issues, that's the only explanation.

"But I wouldn't rule them out tomorrow. I'm sure Mercedes will be quick.

"It's not the easiest circuit to overtake on but if you have the pace eventually you come through. I expect them to be strong."

Ricciardo added: "Qualifying was exciting, to have no Mercedes up here is a surprise to everyone.

"I thought they were playing a few card games yesterday but it seems they are not particularly comfortable here this weekend.

"It's a bit of a surprise - and it's good to capitalise on that."

Vettel believes a front-row lockout was possible for Ferrari, but his team-mate Kimi Raikkonen had to settle for third on the grid.

"We are trying as hard as possible, but in the end I was a bit lucky as I felt really comfortable, and Kimi wasn't," he said.

"It's crucial you feel confidence round the track, you need to be confident in the car."

Raikkonen added: "We had some difficulties so I'm a bit surprised to be in this position after how the car felt today.

"We have to try and do a good job tomorrow and hopefully get two cars on the podium."