Perez is looking forward to working with Button, whose relationship with current teammate Lewis Hamilton has seemingly deteriorated this year.

"I've spoken to Jenson a bit since I signed for McLaren," says Perez. "He seems to be a great guy and I think he'll be good fun as a teammate. He's a very tough guy to beat and is very experienced. He's one of the fastest guys out there."

Not perhaps quite as quick as 2008 world champion Hamilton, who is potentially a daunting act to follow. "For sure, I've got big shoes to fill," says Perez. "I rate him very highly and he's maybe the fastest out there. It's going to be tough to follow what he did."

McLaren bosses are confident he will do just that, despite the fact Perez has not picked up a single point at Sauber since signing for the team.

But it is not the last few races on which the British team reached its decision. Perez, the son of a former Mexican F3 champion and whose elder brother is a NASCAR racer, has always been quick -- he showed that in F1's feeder series competitions.

However, he has been prone to lapses in concentration and occasional errors.

Those have been rarer this year, and he has been notoriously kind on his Pirelli tires, which in turn has helped him bag top-three placings in Malaysia, Canada and Italy.

Where once he was considered aggressive -- and that still flares up on occasion -- Perez has a smooth driving style, akin to Button. It makes him a perfect fit for McLaren's engineers, who can build the car around essentially similar drivers.

His efforts this season were not enough, however, to persuade Ferrari to take a risk on him and sign him as a replacement for Felipe Massa. Perez is a product of the Ferrari driver academy and appeared to be being groomed for a role at the "Prancing Horse."

But Ferrari president Luca di Montezemolo put paid to that back in September by claiming that he lacked the experience required for F1's most successful team. McLaren, looking for a replacement for the Mercedes-bound Hamilton, decided to take the gamble but there is enough to suggest it will pay off.

His departure will prove costly for Sauber, which has brought in Nico Hulkenberg from Force India as a replacement.

Perez has long been backed by Telmex owner Carlos Slim, the world's richest man and a backer that McLaren would dearly love on board. The switching of his investment has cast doubt over the future of Sauber's other driver this year, Japan's Kamui Kobayashi -- who has no major sponsor.

Of his podiums in 2012, March's Malaysian race was arguably Perez's pinnacle to date, scything his way from 10th on the grid to come within a whisker of beating Ferrari's two-time world champion Fernando Alonso to the win, while he also finished second behind Hamilton at Monza in September.

"All my podiums were equally great," he says, "but I'm disappointed I've not had a win. I want to win at Sauber before leaving.

"Sauber has become like a family to me and it's always hard to leave your family. But I have a new family to go to and there comes a point when you have to move up to a new challenge. It will be great to join a new team, to have a new experience."

Before the move, though, Perez feels like he has unfinished business in the season's final two races.

"I still want to give everything until the last lap of the last lap," he says. "I want to give everything I can."