Norbert Haug has conceded that McLaren-Mercedes is lagging behind expectations in pre-season Formula 1 testing so far, but former world champion Kimi Raikkonen has warned against writing the Silver Arrows off come the 2009 curtain-raiser Down Under in Melbourne at the end of the month.

Despite setting initially encouraging lap times, the MP4-24 has languished towards the lower end of the timing screens on five of the last seven days at Jerez and Barcelona, with Heikki Kovalainen winding up bottom of all ten drivers present on Monday this week, somewhat embarrassingly behind the customer Mercedes-powered Force India and Brawn GP machines.

It is believed that the key area in which McLaren is losing out in comparison with its rivals is on the aerodynamic front, with the diffuser or rear wing understood to be the weakest links. It is reported that on at least two occasions, the multiple world championship-winning, Woking-based outfit has applied green liquid dye to the bodywork of the car in order to trace the air flow over it.

Whilst the majority of teams will conclude their pre-season testing preparations at the close of this week's Barcelona outing, McLaren has booked a further four days at Jerez next week, with the new ban on in-season testing making it more vital than ever that competitors hit the ground running in the Australian Grand Prix on 29 March.

"For sure we are not yet where we want to be," Mercedes-Benz Motorsport Vice-President Haug confessed to German newspaper Bild. "The test ban will make developments during the season more difficult, but by no means impossible."

Ferrari star Raikkonen, however - who raced for McLaren for five seasons from 2002 to 2006 - is not convinced the Scuderia's principal rivals will prove to be quite so far off the pace when the competitive action gets underway.

"I don't know if they have problems or what they are doing," the Finn told Italian newspaper La Gazzetta dello Sport during testing at Barcelona. "It is easier to wait two weeks (for Melbourne) to see exactly where people are. Certainly they have been less quick than in past winters, but this does not mean they will not be quick at the first race."