Sebastian Vettel tips Barcelona boost for Red Bull

Championship leader Sebastian Vettel has tipped his old team Red Bull to return to the top in Formula 1.

Currently, the 2017 title looks to be a fight between Ferrari - for whom former Red Bull driver Vettel now races - and Mercedes.

However, after the opening four 'flyaway' races, it is rumoured that a 'B' car in the works by Red Bull could be up to a full second per lap quicker for Barcelona.

"I think [Spain] will be a very close race between Mercedes and us, and I also hope that Red Bull find some pace," said Vettel, who won all four of his titles for the energy drink-owned team.

"There's a lot of rumours around. They are a strong team, they know how to build a quick car so I expect it's a question of when rather than if."

Red Bull are currently in third position in the standings with 57 points to second-placed Ferrari's 135.