Jenson Button insists he already feels part of the McLaren team, just two months after making his move from Brawn GP official.

The defending F1 champion had been part of the Brawn team - in its various guises - since 2003 when he left Renault to join BAR, but elected to switch teams over the winter when Brawn was taken over by Mercedes.

Button's move to Woking wasn't made official until the New Year when his Brawn deal came to end, with the Briton making his debut for McLaren this weekend in Bahrain.

While he admits that moving teams can be tricky, Button insisted he already feels at home in his new team and was hungry to help the Woking-based squad bounce back from a challenging 2009 campaign.

"I was with my previous team for seven years, so moving teams can be tricky," he said. "It is a completely new environment, it is a real challenge and most of us do not really like change, but it has been good. Even after sort of two months I really feel part of the team. We have not even gone racing yet and I feel a big part of the team. I have always worked very hard to make myself fit into a team reasonably well but the team have been great. They are so hungry for a good season.

"Last year for them was not the best and it has made them hungry for success this year. It has been good and having the simulator there has helped me a lot to get used to the environment of being in this car. I spent a lot of time at the factory, not just with the engineers, just spending time at the factory, so I am part of the furniture there.

"Testing has gone well as well. It is important to really use every second or every minute you are with the team as it comes around very quickly. We have Friday and Saturday morning before qualifying but it is not a lot of time, so you have got to be ready for when you arrive here in Bahrain."

Button's title bid last season was built on strong early season form from the Brawn team, with six wins in the opening seven races being the catalyst for his championship success.

With that in mind, Button admitted that a strong start to the season would be important again this time around.

"I think it's important to be quick out of the blocks," he said. "If you look back, normally the guy that really fights for the championship and gets the championship is strong from the word 'go', so yes, I think it is important for all of us to be up there at the front here in Bahrain.

"The competition is very fierce, I must say, but that's why it is exciting. For a fan of Formula One, this season should be electric, it really should be. If it's not, we're doing something seriously wrong. It's obviously great to have Felipe back after his horrific accident last year. Great to have Michael back because it makes me feel young again!

"Looking at this race, I don't think there have been so many competitive drivers in competitive cars for a long time, so it's great to see."