Apr.28 (GMM) McLaren boss Ron Dennis has rubbished Sir Jackie Stewart's advice that Lewis Hamilton should employ an external "coach".



The former triple world champion had suggested that 23-year-old Hamilton's recent slump in form could be blamed on him trying to "go from kindergarten to university overnight".



"Even the great Tiger Woods has a man with him," Stewart pointed out.



But Dennis told reporters at Barcelona that Hamilton proved last year that he already has what it takes to be a winning grand prix driver -- and all the help and resources he needs at his disposal within McLaren.



"And who has a coach? What top driver has a coach? You are talking about something that doesn't exist," Dennis added.



"I would never, ever have a driver that had to be guided by a third party on how to drive a racing car," he said.



The British driver's form since winning the Australian grand prix, however, has given his bosses pause to reflect on some of Hamilton's weaknesses -- including his desire to satisfy the enormous external requests for his time.



Dennis' deputy Martin Whitmarsh mused at the weekend that Hamilton is "too giving of himself", and Dennis believes the 23-year-old is "too hard on himself" -- such as in speaking openly with the press after his poor performance in the Bahrain grand prix.