Vettel's F1 season going from bad to worse

MONACO (AP) Sebastian Vettel's season got even more frustrating on Sunday after the four-time defending Formula One champion spent most of the Monaco Grand Prix watching from the garage after car failure ended his race.

The German driver had already won two races by this stage last season, but this year he has only one third-place finish and is down in sixth overall behind Nico Hulkenberg and Daniel Ricciardo.

Not helping matters, Vettel's Red Bull teammate Daniel Ricciardo has back-to-back third places in Spain and in Monaco. The Australian driver seems much more at ease than Vettel with the engine regulation changes that came in at the start of the season.

''I felt quite helpless in the car, so I was asking for an answer of what we could do, but there wasn't anything at that stage,'' Vettel said. ''It's disappointing. I had a good start and then we lost boost pressure from the turbo, so I had no power and had to retire.''

Vettel moaned ''come on guys'' over the race radio when he was called into the pits, before changing tact with a more diplomatic ''I mean you're trying everything.''

He had also complained of being ''stuck in first gear,'' and team principal Christian Horner moved to reassure his star driver afterward.

''First of all we have to apologize to Sebastian for an issue with his power unit,'' Horner said. ''It's frustrating that, after making a good start, his race came to a very premature end.''

It is some contrast to last season, which Vettel rounded off with nine straight wins. He won 13 of 19 races and looked untouchable, retired only once - at the British GP - and finished on the podium 16 times as Red Bull crushed all the opposition.

''We will move forwards, and it will be good for us soon,'' said Vettel, who also retired from the season-opening Australian GP.

Ricciardo is nine points ahead of him heading into the Canadian GP in two weeks' time.