Mercedes boss Toto Wolff insisted that the team wasn't worried by its relative lack of pace compared to their rivals in Friday's two practice sessions ahead of this weekend's Bahrain Grand Prix.
Valtteri Bottas was second fastest in FP1 albeit three tenths behind Red Bull's Daniel Ricciardo. Lewis Hamilton was only fifth fastest. However, the daylight session wasn't representative of night time qualifying and race conditions.
More worrying for Mercedes was the outcome of FP2, which was held under the floodlights at Bahrain International Circuit. Bottas and Hamilton ended the day half a second off the pace of the two Ferraris.
But Wolff said there was nothing for his team to be concerned about.
“They were in a pretty high-power mode when they were on the lap," he told Sky Sports F1 after the end of FP2. "So it isn’t so worrying. But it is a good lap.
"What we have seen in Melbourne and again here is that at various stages the teams are close together," he added. "I can’t really judge."
Wolff was asked how he could be so certain that Ferrari were in a high power mode on Friday.
"It’s quite amazing," he said. "We have GPS data, so you can follow the traces of every car.
“You can see that when you overlay the data, suddenly on the straights they gain much more time," he continued.
"In the corners it’s still the same," he noted. ""You can see that in detail.
"It’s become very transparent for the engineers how much somebody has turned up the power," he explained. "And how much downforce, and how much drag everyone is running."
Mercedes rivals had been complaining of Mercedes' ability to turn up the engine power when it counted. It was dubbed 'party mode', although Hamilton insisted that his pole lap in Melbourne hadn't been down to any such gimmicks.
In Thursday's press conference, Hamilton had suggested that Ferrari's power unit was now a match for that of Mercedes.