Jenson Button reckons Nico Rosberg will be 'surprised' by Lewis Hamilton's speed next season when the two are paired up at Mercedes.

Button has seen first hand over the last three years just how quick Hamilton can be with an ill handling car and he believes that will come as a bit of a shock to the German, who has more often than not got the better of his former sparring partner, Michael Schumacher.

"I think he'll probably get a bit of a surprise at his speed," Button told ESPNF1.com. "I know he's been his team-mate in the past but I think he'll be surprised at how Lewis can get performance out of a bad car.

"I think that will be the biggest thing."

Button doesn't, however, foresee any problems between the two: "I think Nico knows him pretty well," added the McLaren driver. "I think Nico knows Lewis better than I do [actually].

"They've worked together before and I'm sure he knows what to expect [from their working relationship]."