Toto Wolff has admitted he was surprised to hear Ferrari reassure Sebastian Vettel about his 'number 1' status.

After a winter of speculation that Charles Leclerc could immediately be gunning for the title in 2019, new boss Mattia Binotto said it will in fact still be Vettel with "priority".

"Mattia has a daunting task ahead of him, and I have the impression he wants to do it in his own way," Wolff, the team boss at rival Mercedes, said in Barcelona.

"Team orders is always a controversial topic," he added. "To say such a statement at the beginning of the year is quite something."

However, Wolff says he thinks Binotto will be a good replacement for ousted Ferrari principal Maurizio Arrivabene.

"I have known Mattia for many years, as the engine boss at Ferrari, then as head of the technical department, now as team leader," he said.

"He's a lightning speed guy who knows exactly what he's doing."

Indeed, Vettel impressed with his laptime on day 1, with Mercedes further back. Is Wolff worried that Mercedes' rivals have finally caught and passed the German team?

"I always find regulation changes so exciting because it means these different interpretations," said Wolff.

"For example, we can see on the Ferrari or the Sauber that they are pursuing a different front wing concept compared to their opponents.

"I see a lot of innovation, and clearly we have that on the radar," he added. "On the other hand, we cannot be distracted.

"We always go in the direction of evolution with our cars, and many of our most distinctive changes are hidden.

"We have a good package," Wolff insists, "but where it takes us, nobody can say right now. World championships are no guarantee that you will stay there, and the performance of Ferrari on the first day underscores that."