The 2008 world champion will join a team whose form has swung wildly this year. The class of the field at China - where Nico Rosberg scored his breakthrough win – Mercedes failed to score in five straight races over the season run-in.
Hamilton estimates the team's current deficit to the frontrunning teams to be over one second per lap, but insists it is not completely unrealistic for that gap to be closed over the winter.
"It looks like in Brazil Mercedes were 1.1 seconds behind, so we have got a long, long, steep curve to climb, but I don't think that's impossible," Hamilton told Sky Sports News.
"I think the guys have great potential and that's why I'm going there. I don't see it as a short-term thing."
Hamilton did however stress he would need half a year to begin having an impact on the teams' development, making 2014 his primary focus.
"I don't get in the car until February so I won't be able to have a big enough impact until at least six months down the line," he explained.
"I really think 2014 has to be the most important year, or the most competitive year.
"But I don't see why we can't try and clinch a few podiums.
"If we can get some wins next year - if it just happens to go really, really well - then we will be smiling, but we'll see."
In contrast to his downplaying of expectations at Mercedes, Hamilton admitted McLaren is poised for a strong season in 2013.
"I feel positive about their car next year," he said.
"The car already from this year was pretty awesome and next year is an evolution of this car.
"I think next year they are going to have a championship contender, for sure."