Sebastian Vettel is not sure Ferrari can hit back at the increasingly dominant Mercedes team next weekend in Barcelona.

In the winter, Ferrari dominated the pre-season tests which took place at the Spanish grand prix venue.

But on Sunday, Mercedes broke Williams' 1992 record for the most consecutive 1-2 finishes.

"Boring," German Vettel said in Baku. "Isn't it boring?

"And not just the last four races. This has been going on for more or less four or five years."

Not including a growing internal rivalry between Vettel and Charles Leclerc, there appears to be a few problems at Ferrari.

One is that Mercedes is incredibly consistent. And another is that Vettel is not comfortable with the 2019 car, which he says is hard to get in the "tyre window" from "lap to lap".

"There is a lot of work ahead of us," Vettel agrees.

"I hope we are stronger in Barcelona and we have a lot of things coming for the car. But I think after the first four races we are not the favourites going to Barcelona.

"Our car is not slow, but unfortunately Mercedes is really fast. And it seems somehow easier for them to always get everything out of the car and the tyres."

Ferrari boss Mattia Binotto agrees that despite Mercedes' apparent dominance, "the gap in pace is not as big as the scoreboard shows".

His Mercedes counterpart, Toto Wolff, agrees with that. "I still believe that Charles Leclerc was the fastest here," he said in Baku.

"But as in Bahrain, they could not put everything together."

Wolff also hit back at Vettel's claim that Mercedes is making F1 "boring".

"I don't think it's boring," he insisted.

"I think you look at the Formula 2 race and there are lots of incidents and safety cars, but the Formula 1 drivers race a lot more cleanly. We are talking about the best drivers in the world," said Wolff.

"As a fan, I would like to see different winners and a big fight from start to finish, but I lead the Mercedes team -- and I do everything so that it performs as well as possible."