The Woking-based squad introduced a number of upgrades to the Mercedes-powered MP4-29 at last weekend’s Grand Prix in Spain, but neither Jenson Button nor Kevin Magnussen were able to break into the top ten in the race.
With the next two rounds of the championship taking place at the atypical Monaco and Canada venues, Boullier believes that the races in Austria and Britain will provide a better barometer of progress - and could also dictate the team’s future development path.
“I think the real question about how capable we are at catching up and how fast we can catch up will be from Austria to Silverstone,” he told a McLaren-Mercedes teleconference on Tuesday.
“I’m not saying we’re going to win at Silverstone, I’m saying we’ll know more about our capability to catch up by these races.”
Asked if a lack of progress by Silverstone could see McLaren turn their attention to next year, Boullier said: “I don’t think we will shift our focus onto 2015, […] but it’s possible that we will draw a line after Silverstone and we may go with more radical concepts.”
Despite a disappointing weekend in Spain, which saw McLaren slip to sixth in the constructors’ standings behind Williams, Boullier was adamant that the team had gained ground.
“In Barcelona we weren’t the fastest, but we were at the top of the midfield and then something has gone wrong, like the power unit problem for Kevin in qualifying or the poor start for Jenson in the race,” he explained.
“Following all of our data analysis, all of the upgrades actually worked, except one part in high-speed corners.
"But the car was not worse - we know this. We are now in the rebuilding process of the aero department, we have the car we have, so we need to so far develop the car like it is.
“We have seen very, very significant progress in the wind tunnel in the last few weeks, so I think we need to just understand where we are, where we want to go, and this is now where we are just defining.
“It’s true that we’re starting from quite far (back), but we have a very good rate per week in terms of development.”
Although Boullier thinks it will be hard to gauge McLaren’s progress in Monaco, he said he expects the MP4-29 to perform better in the Principality.
“Monaco could be not bad for us,” he said. “Our car is well-balanced in low-speed corners and very driveable, so Monaco could hurt us less.”