A report in the Sunday Observer newspaper said the 2008 world champion "won't achieve" his target of becoming a multiple world champion with the Woking based team.
The outfit's MP4-26 car has been unreliable and uncompetitive in pre-season testing and McLaren now faces "a desperate struggle" to keep 26-year-old Hamilton on-board, the report said.
"I am not here to race 10 years and only win one or two world championships," Hamilton is quoted as saying, amid reports pacesetting Red Bull could be the ideal alternative team.
"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.
The 2008 world champion, however, defended his current team, even though the Daily Mail also interpreted the comments as Hamilton "spelling it out to McLaren".
"I want to be one of the most successful formula one drivers of this generation, so I think you have to continue winning and prove yourself time after time for people to know you are the best," added Hamilton.
The Daily Mail said: "The reality is that he will not abandon the team unless this season is a total disaster and there is a vacancy in a rival competitive team."
The newspaper also said Red Bull is a viable option for Hamilton in 2012, even though that team might risk destabilization by ousting Mark Webber.
Red Bull team boss Christian Horner said: "Seb (Vettel) has never made any request, or claim, as to who he partners. He has a complete inner-confidence in himself."