Lewis Hamilton and Jenson Button admit to car worries
McLaren have work to do - Hamilton
McLaren's Lewis Hamilton and Jenson Button are concerned their new car is already lagging behind their rivals ahead of the new season.
The MP4-26 was belatedly unveiled at the second Jerez test with technical issues affecting Barcelona testing.
"When we see our times a little bit off we know we've got a bit of work to do to catch up," Hamilton told BBC Sport.
And Button added: "We've not done as much running as we would have liked, which has hurt our set-up."
After choosing to focus on development, McLaren delayed their car launch and missed first the first pre-season test in Valencia, while things did not go smoothly for the car's debut in Jerez because of a lack of spare parts.
Hamilton, who finished fourth in last season's championship as Red Bull's Sebastian Vettel took the title, clocked up a useful 107 laps on the final day in Catalonia.
Hopefully things are going to run more sweetly at the next test in Barcelona
But Hamilton, 26, finished 1.378 seconds off Felipe Massa's pace-setting time for Ferrari. And after Button had spent two days at the wheel, he concluded: "I still don't know where we stand."
Hamilton, however, did not deliver a wholly downbeat assessment of the new model.
Speaking at a media day at Surrey's Dunsfold Aerodrome, Hamilton continued: "We left it [unveiling the car] a bit later... and perhaps it's not played right into our hands.
"We've good things in the pipeline, and we definitely improved in the last couple of days' testing."
McLaren are understood to be working on upgrading their exhaust package as they attempt to close the perceived gap on pacesetters Ferrari, who also have championship runner-up Fernando Alonso in their line-up, and Red Bull, who are led by Vettel and Mark Webber.
The prospect, therefore, of further improvements before the revised season-opener in Melbourne (25-27 March) was also a source of optimism for Button.
"We do have four more days and hopefully things are going to run more sweetly at the next test [again at the Circuit de Catalunya beginning on 8 March] - we get a lot of laps in, and then we can improve the base we have," said 2009 champion Button.
"When I first jumped in the car my first reaction was not 'wow, we're going to blow everyone away'.
"But then I don't think anyone would have felt that because the car has a lot less downforce and the tyres [Pirelli] are working very differently to the previous tyre [Bridgestone]."
Next season all teams will race with less downforce because of rule changes which ban the double diffuser and the aerodynamic aid the F-duct.
Lack of downforce cost then-world title holder Hamilton dear in 2009 when McLaren were two seconds off the pace at the first test - Button eventually crowned champion in a Mercedes-powered Brawn.
It was little wonder then that Hamilton was also uneasy that his new McLaren had brought back memories of the '09 version.
"This car is closer to the '09 car in the sense of downforce," said Hamilton. "The '09 car was terrible as it was hopping, three-wheeling through corners, locking up, and it had no downforce.
"This car doesn't lock up, it doesn't three-wheel, and it handles really nice, better than last year's car, but it just doesn't have as much downforce.
"Because the regulations have changed, it's a similar downforce level to '09. We have a little more, but it's not far off, so it feels weak in that area. Hopefully we've more downforce coming onto the car."
Anthony Hamilton had managed his son's career since he was eight
Meanwhile, Hamilton has revealed he is "closer" to revealing his new management team having spent last season without one after parting company with his father as manager 12 months ago.
"Nothing has been signed or fully firmed up, which is why I've not announced anything," added Hamilton.
"But I'm really hopeful in the next week or so we have an announcement for you guys, definitely before Australia."
IMG, who have Tiger Woods and Roger Federer among their clients, and Simon Fuller, a long-time associate of David and Victoria Beckham, are the two leading contenders.
"One is 85%, and the other is still hanging in there," revealed Hamilton.
"It's a big decision to sign with someone for a period of time, but I'm confident with what I'm going to do, and you'll find out very soon."
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