McLaren duo say Red Bull's resurgence comes as no surprise

The Briton was beaten to pole position at Sakhir by Sebastian Vettel, whose brilliant performance came just a few days after he argued that Red Bull was not in a position to win races yet.

But with the performance showing that there is good potential in Red Bull's RB8, Hamilton reckons that the reigning world champion outfit has to be taken seriously.

"They are second in the constructors' championship, so I don't think they have ever been gone," explained Hamilton. "They have just not been as quick as us in qualifying for a couple of races, and at this place obviously the temperatures are a little bit higher.

"So unless they bought an upgrade package for this weekend, they are obviously getting the tyres more into the working range. They have always had a [competitive] car since race one, and their race pace has been their strong part of the weekend - so I don't think anything has particularly changed."

Team-mate Jenson Button agreed with the verdict on Red Bull - which he thinks is firmly in the hunt for title glory.

"I think over the last three races they have not had the outright pace, but they have still done a very good job of collecting points," he explained. "We saw that they were competitive, so I think they are good.

"They are looking like they will be contenders for the win, and it is going to be tough to beat them, but it is never easy. We have always got somebody to fight for a good result."

With the formbook fluctuating quite dramatically over the opening races of the season, Button is convinced the championship will be won by ensuring consistent results in the type of crazy races we have got used to seeing this year.

"I don't think we should be looking to better the last race, otherwise we are going to get into a position where we just cannot have a better race," said Button, when asked if the Bahrain GP would be a similar spectacle to China. "We can expect too much.

"I think in general the races here have been very good. Not all of the races will be that exciting, but if the average race is exciting like we found so far this year, it is great. So I think there will be some good fights.

"It is not one team at the front that is going to walk it. I think the Red Bulls are strong, we are strong, but also just behind us you have Nico [Rosberg], and [Daniel] Ricciardo - it was a great lap by him. And then you have got the Lotus.

"It is going to be an interesting race and Michael [Schumacher] is a long way back but he has got every set of tyres he can use for the race - and they are brand new. He could also spring a surprise."