"The only teams that can give him a winning car are Ferrari [ Images ] and Red Bull. Lewis is no longer the key in the driver market -- Red Bull's Sebastian Vettel [ Images ] is," the Sun quoted Watson, as saying.
It comes after Hamilton hinted that he might look for a move if the Woking-based team is unable to match the Ferrari of Fernando Alonso [ Images ] and the genius of Adrian Newey at Red Bull.
"I am not here to race 10 years and only win one or two world championships. I want to be one of the most successful F1 drivers of this generation so I do want to win more world championships and I think you have to continue winning and prove yourself time after time for people to really know that you are the best," Hamilton had said.
"I can't say right now that people can say he was clearly the best in the world. I have only been here for four years so I have got a lot more to do," he added.
Hamilton had scored his first title success three seasons ago having almost become world champion in his rookie year of 2007. Since then, the 26-year-old has found the going rather tougher.
He finished fifth in the 2009 drivers' championship after McLaren overcame a difficult start to the season and was fourth in the standings last year, despite remaining a title challenger until the final race.
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