McLaren has 'significant' upgrade for Spain

The Woking-based outfit achieved its best result since last year's Hungarian Grand Prix in Russia with Fernando Alonso finishing sixth and Jenson Button seventh.

Boullier said after the race that McLaren would have matched the pace of Williams, which finished fourth and fifth, had it not had to save fuel.

"We have a significant upgrade for the next race in Spain," said Boullier.

"Monaco should suit us, so we should be more competitive in Monaco, but Barcelona I don't know."

Boullier said he was happy with the Honda's general engine performance but added it "could be a little bit better".

Alonso agreed with his team principal that there is reason to be optimistic for the upcoming races.

"The potential is there and there are some circuits coming up now that will suit our car even better, like Barcelona and Monaco," he said.

"So [I have] high expectations for those and hopefully we execute it OK, those weekends, and we maximise those points."

Button added: "We've got a lot more points now at this time of the year compared to last year so it's really good for the team.

"The next race is still a little bit difficult for us on outright pace but then in Monaco [we can hope for] another good points haul."

However, the 2009 world champion pointed out McLaren's Russian GP result still owed a lot to the misfortunes of other teams.

"You have to look at [the fact that] two Red Bulls [had problems] and a Ferrari didn't finish - that’s three places," he said.

"It's a lot of positions gained through other peoples' incidents. You have to take it when you can and it's good that we were able to - we couldn't in Bahrain [where Button retired after six laps] but we were able to get both cars in the points here."