By PAUL LOGOTHETISAP Auto Racing Writer

MADRID − Formula One arrives in Europe this weekend with defending champion Jenson Button leading a wide-open championship and Michael Schumacher desperately looking to turn around a disappointing comeback.

Button is coming off his second victory of the season for McLaren at the Chinese Grand Prix and enters the Spanish GP with 60 points, ahead of a pursuing pack of six rivals within 20 points.

“At the moment I've just had my head down and focusing at every race we get to because it's been nonstop,'' Button said.

Mercedes driver Nico Rosberg is second with 50 points, one better than Ferrari's Fernando Alonso and Button's teammate Lewis Hamilton, while Sebastian Vettel, Felipe Massa and Robert Kubica lurk close behind.

Schumacher, however, is nowhere near the leaders with only 10 points.

The seven-time champion needs a sharp improvement if he is to get into title calculations. Mercedes has made a major aerodynamic upgrade since China, hoping to boost results for the 41-year-old German, who has returned after a three-year absence from the sport.

“Our step forward in Barcelona will be bigger than you can make at each race during the flyaways, but it would not be realistic to expect us to suddenly be competing right at the front,'' said Schumacher, a six-time Spanish GP winner.

Flavio Briatore, Schumacher's former boss at Benetton, thinks things will just get harder for Schumacher in what's shaping up as one of F1's most competitive seasons.

“I don't know how he can recover. The competition is fierce,'' Briatore said. “I've always said that it would be difficult for him to stay ahead of Rosberg. You can't come back in such a competitive sport after four or five years.''

Mercedes teammate Rosberg has improved with each race and comes to the Circuit de Catalunya feeling “extremely motivated.''

“I am hoping for a better race in Barcelona than I had in China and, of course, I would not mind having had better results so far,'' the German said.

Although Red Bull arrives with questions about how to transform its qualifying pace into stronger race performances, it can be reassured that the past nine Spanish GP winners have started from the pole position.

Vettel, who has 45 points, has started on the pole in three races so far, but has won only in Malaysia after teammate Mark Webber topped qualifying there. Reliability continues to hamper Red Bull's progress to becoming a serious challenger for the championship.

“(We're) definitely not rapt with the results. We've left some change on the table, there's no question about it,'' Webber, who has 28 points, said on the BBC website. “We just need to make sure we have clean weekends and roll everything together.''

Red Bull has not produced a version of McLaren's F-duct, an aerodynamic device that produces greater speed on straights. Ferrari has done more work on it since China and plans on trying it out at Friday's practice sessions before deciding whether to race with it.

“Red Bull is higher up in the standings and has a lot of speed, but on the track we're catching them, while McLaren knows how to bring out their cars just right without too much pressure, but we do too,'' said Alonso, who opened the season with a win. “Ferrari is still the favorite for the championship.''

Alonso, a winner in his home race in 2006, expects Saturday's qualifying to be the key this weekend, which again makes Red Bull the favorite.

“Historically you need to start at the front,'' the Spanish driver said. “Starting (from the) pole position gives you the best chance to win the race.''

Kubica, with 40 points, has been the surprise of the season for Renault.

“If you had said to me at the start of the season, or even after Bahrain, that I would have scored 40 points and three top-five finishes, I would have been more than happy,'' the Polish driver said. “The next race will be another big test for us because the return to Europe is usually a turning point in the season with many teams planning big upgrades to their cars.''