Ferrari F1 team must watch out for midfielders - Fernando Alonso

Ferrari is currently third in the standings, but only 26 points ahead of sixth-placed McLaren.

The Italian squad is in front of Force India and Williams, but the British team has performed strongly in the last two races and Alonso reckons it will be quick again at the British Grand Prix this weekend.

"I think in Austria it was not only Williams who was our biggest rival. We were in a group of McLaren, Force India, Toro Rosso. So it was not just Williams, unfortunately," said Alonso.

"So we need to keep improving and try to get some margin on those teams, especially for the constructors' championship, because we have a threat of Williams, Force India, McLaren. Red Bull is a bit ahead of us at the moment.

"There are some interesting things that could happen in the constructors' championship so we need maximum effort and concentration on that. I expect here Red Bull will come back in strong form [at Silverstone] because it's an aero circuit.

"But I think Williams will be strong. I don't think it was only Austria that was good for them. In Canada they were also very good, and I think here they will be a threat.

"If we don't score points and finish sixth or seventh in the championship that will hurt the team for next year, because of the economic prize and things going on."

THE BATTLE FOR THIRD IN THE CONSTRUCTORS' CHAMPIONSHIP:

1 Mercedes 301
2 Red Bull 143
3 Ferrari 98
4 Force India 87
5 Williams 85
6 McLaren 72
7 Toro Rosso 12
8 Lotus 8
9 Marussia 2
10 Sauber 0
11 Caterham 0

Alonso, who has won races in all seasons since he joined Ferrari in 2010, admitted he does not believe he will take any victories this year.

The two-time F1 champion has finished on the podium just once this year.

"If I'm honest with you I'd say no, it's not possible to win this year," he said.

"It's what I'm thinking inside. But also in 2011 I thought it was not possible to win and we won at Silverstone, so anything can happen.

"We will try to do the best we can and if one opportunity arrives we will take it. It's extremely difficult with the performance we are showing."