SILVERSTONE, England (AP) — Ferrari was left guessing after one of its worst qualifying sessions this season at the British Grand Prix on Saturday, a result that damages its bid to challenge Red Bull's Sebastian Vettel in the drivers' championship.

Fernando Alonso qualified 9th and Felipe Massa 11th.

With 12 races remaining, Alonso trails Vettel by 36 points. He acknowledged this week that the team needed to step up its performance to catch Vettel and do more to rebound from several poor races.

"This weekend has been complicated for us by problems that we haven't managed to get on top of, concerning various aspects such as the balance of the car, its driveability and performance," said Alonso, who also blamed some poor tire chooses for the team's troubles.

"We can consider this the worst Saturday of the season so far, having never finished so far down, but now we must react immediately to try and return to the form we showed at the start of the year."

Vettel said it was premature to count out Alonso.

"It's not good news for him. For sure he wanted to be a little bit higher up as well as Ferrari," he said.

"It's a bit of a surprise. I think they've been very competitive here the last couple of years but this is also a circuit, let's not forget, where the balance is very important so even if you have a good car, if it's not coming together it can make a big difference, especially over one lap. In terms of race pace and tire wear, they will be strong tomorrow and surely, should everything go as per plan for them, they will finish higher up than 10th."

Alonso is unlikely to be helped by Massa, whose poor run of form continued at Silverstone. After crashing in practice and in the race at Monaco and then in qualifying in Canada, he also found the barrier on Friday at the British GP. He never seemed to recover from that setback.

"It was an extremely difficult day as we did not have the car we were expecting and we had no grip whatsoever with new tires. Compared to other cars, we struggled to put together a good lap," Massa said. "The time lost when I went off the track yesterday and the interruption this morning to change the engine definitely cost me valuable kilometers, and in qualifying I lacked the few tenths necessary to make it through to Q3."

The team came into 2013 full of confidence that it had the car to earn its first championship in four years and help Alonso win his third title. The Spaniard has won twice to remain a contender but he has been dogged by several poor finishes — crashing out in Malaysia and finishing eighth in Bahrain when his DRS system malfunctioned.

The team and Alonso understand they cannot afford another poor showing this weekend if they want to catch Vettel, and remained cautiously optimistic they can still turn in a good result on Sunday.

"We can be more confident when it comes to the race and we will be counting on the performance we have seen over a long run, which is encouraging," Ferrari technical director Pat Fry said. "During the opening laps it will be important to try and make up a few places. Then, our strategy will be aimed at helping the drivers as much as possible in their efforts to close up to our direct rivals."