Sam Michael says McLaren are not yet willing to throw in the towel despite a "brutal" weekend in Canada.
McLaren's run of 64 grands prix in the points came to an end last time out in Montreal where the team lacked the pace in both the wet and the dry.
Sergio Perez and Jenson Button could only manage 12th and 14th in Saturday's wet qualifying with both drivers barely improving in the dry on Sunday.
The duo finished 11th and 12th with Perez ahead of Button and both drivers a lap behind race winner Sebastian Vettel.
"It was a brutal weekend for the team," the McLaren sporting director told Sky Sports F1.
"To be lapped by the top cars, that is probably the most important thing for us to concentrate on. We are still developing the car and it is responding, just not as fast as we had hoped.
"I think the picture of Montreal was painted blacker than what it probably is as we have made progress over the last number of races and I think for Silverstone our thoughts are that we will definitely be more competitive than what we were in Montreal."
Michael, though, is expecting a better showing at Silverstone where he believes latest updates will work better.
"No question they will work better than they did in Montreal.
"We have a lot of things which we will do in practice at Silverstone and hopefully they will yield even more performance out of this car.
"In terms of taking a big step up to the front that is probably unrealistic and we just have to try and take small steps each time."
The former Williams man added that McLaren will not throw in the towel nor will heads roll.
"I don't think you ever get to a point where you write it off - we will always be pushing to improve the car and get good results right to the end.
"In terms of bringing development parts to the car, the August shutdown is going to be a natural point for most teams to start ramping down this year and putting everything into 2014."
He added: "If you focus on sacking people, to start with you have to be very careful because first of all you could sack the wrong people and secondly the people who are responsible for this car are part of this company and they are committed to it.
"They are very good engineers and designers who have produced very good cars in the past and they are going to be the best people to fix this car and produce another very good car in the future."