McLaren will press ahead with their 2013 car rather than switch to last year's challenger despite their disappointing start to the season.
Team principal Martin Whitmarsh was forced to concede McLaren's difficulties after the first two practice sessions for the season-opening Australian Grand Prix and things did not get any better with the MP4-28 more than two seconds off the pace over the course of the weekend.
McLaren are working on resolving the issues but there had been speculation that the team would revert to the 2012 car in a bid to return to competitiveness, but Whitmarsh insists that has not been discussed.
"All our efforts are currently focused on understanding this year's car, not considering last year's car," he said. "We believe we can fix those issues."
Jenson Button showed good pace in the wet conditions during qualifying but he struggled when the track dried out, qualifying 2.95 seconds slower than polesitter Sebastian Vettel. Whitmarsh is confident the team can get to the bottom of the problem but he knows improvements may take some time to come through.
"At the moment we have to work hard on this car," he went on.
"We know it has got some areas of high potential and we know it has potentially more downforce than last year's car.
"We just need to understand it and make sure [the performance] is accessible.
"We have all had cars in the past that have been difficult to get performance out of, even though some of the [downforce] figures are quite impressive.
"This car seems to be difficult in that regard and we need to work on it, understand it and fix it."