The buck will stop at Martin Whitmarsh if McLaren cannot quickly emerge from its early 2013 slump, according to former team driver David Coulthard.Having lost team stars Lewis Hamilton and Paddy Lowe ahead of the 2013 season, the team struggled markedly in Australia with the radical new MP4-28.Team boss Whitmarsh might ultimately shoulder the blame, Coulthard wrote in a column for the Telegraph.'FAILURE IS NOT AN OPTION'Coulthard, who drove for McLaren between 1996 and 2004, said: "You cannot escape the fact that there is pressure upon Martin Whitmarsh as team principal, for in the end, the captain of the ship is responsible for its navigation."F1 is not a sport where people shy away from responsibility. Any evidence of a lack of commitment, lack of focus, or an inability to deliver consistently, is immediately addressed."Failure is not an option." There has been talk of McLaren scrapping the MP4-28 in favour of reverting to the winning 2012 car, but that cannot be done in the very short term.Jenson Button said: "Am I excited for the next race (in Malaysia)? We certainly will not be quick."On the possibility of the 2012 car returning to action later on, Whitmarsh is quoted by Italy's Autosprint: "Purely from a technical points of view, it would be possible."As the pressure ramps up, Button backed his boss: "Everyone looks up to Martin. It's difficult to always be strong, but he is doing a bloody good job. There is no finger-pointing."We want to improve, but it is going to be a long journey for us I think." Stay with Wheels24 for the 2013 Formula 1 season – fresh reports every day.