BARCELONA, Spain (AP) _ Fernando Alonso arrives at the Spanish Grand Prix in a fight for the Formula One championship.

The two-time defending champion will line up on the Circuit de Catalunya on Sunday atop the driver's standings, just as he did in 2006 when he easily won his home race for the first time with Renault.

Now, the big difference is that the championship race is wide open. And Alonso is driving for McLaren.

``To arrive in Barcelona with the championship lead for the third straight year is something that is special but it is the same as the previous year,'' Alonso said Thursday. ``The pressure is the same.''

Alonso and McLaren teammate Lewis Hamilton are tied with Ferrari's Kimi Raikonnen with 22 points after three races.

McLaren leads the constructors' standings with 44 points, five more than Ferrari.

Both teams arrive in Barcelona after four weeks of development that is unlikely to yield an advantage to either team.

``We need to wait and see for Saturday after qualifying,'' the 25-year-old Spaniard said. ``Until that moment we will not see how our car compares to the Ferrari. It will take more time to be 100 per cent confident and comfortable in the car.''

Alonso led a McLaren 1-2 finish with Hamilton at the Malaysian Grand Prix last month. Despite following that up with a fifth-place finish in Bahrain, Alonso is pleased with the results of his MP4-22 car so far, though admits he is still figuring it out.

``(Bahrain) was a bad race. You have one or two of them a year where you don't get the perfect balance in the car and you lose a little bit of confidence but this happens to everyone,'' Alonso said. ``We've had a really good start with five of six possible podiums. We've demonstrated we're a good team and we want to win.''

Ferrari will be motivated knowing former driver Michael Schumacher will be in the pit lane this weekend. The seven-time world champion will be attending a race for the first time since his retirement from F1 last year.

``I'm very happy about it and he will surely be able to give us an extra boost and enthusiasm,'' Ferrari driver Felipe Massa said.

Massa sees Schumacher as part of the reason he is only five points behind the leaders after his win in Bahrain last month.

He also believes the F2007 car should push his championship aspirations and continue to set the pace on race day.

``The testing is important to show speed and improvement and I think we've showed it,'' Massa said. ``The team was very competitive in the last few races and we expected it to be competitive anyway which is why we keep working hard.''

Hamilton, who became the first rookie driver to begin with podium finishes in his first three races, will be looking to upstage his Spanish teammate and win his first F1 race in front of a sellout crowd of at least 131,000 fans.

``I'm not only excited to get back in, but we have definitely made a step forward with the car,'' the 22-year-old English driver said. ``We just need to work and continue with the same performances we have the last couple of races.''

Hamilton finished second in Barcelona last year on his way to winning the GP2 title.

The track won't quite be the same as he will remember, with the last two bends being replaced by a chicane that flicks left then right to allow for more passing.

BMW Sauber is third in the constructors' standings with 18 points and driver Nick Heidfeld has earned points in each race. He is third with 15 points.

Practice is Friday and Saturday morning, with qualifying in the afternoon. Sunday's race has increased by six laps to 66 on the 4.627-kilometre circuit.