Lewis Hamilton has called for "calm" on his side of the McLaren garage after admitting he was at a loss to explain why he struggled for pace in Practice Two.

As has often been the case this year, Hamilton got off his grand prix weekend off to the perfect start in the day's opening practice session by setting the fastest time, his margin of superiority three tenths of a second.

However, the second session proved far more problematic for the title-challenging Englishman as he failed to set a representative time on the faster super-soft tyres and then cut his race simulation short after running off the circuit at the first corner - an incident which saw him wave his hand in clear frustration.

It meant Hamilton ended up only eighth on the final timesheet, eight tenths of a second off the pace of the dominant Red Bulls, although his benchmark time from the earlier session was still the third best of the day.

But with his struggles in the second session proving the more immediate concern, a somewhat perplexed McLaren driver told Sky Sports News' Rachel Brookes: "The first session was fantastic so I don't really know what's happened in this session."

"We need to analyse and I need to look [at what happened]. Wind directions change but it didn't seem to affect other people so I have to try and figure that out.

"We've got time. We have to be calm tonight and try to figure out where we want to go in direction with the setting of the car. Jenson obviously wasn't in such a bad position today so the car definitely has some pace there we just need to extract it."

Indeed Button's performance in the second session should prove more than a silver lining for Hamilton given the Briton marginally outpaced the Red Bulls on his longer run at the end of the day.

Nonetheless, although happy with his MP4-27's handling over the longer runs, Button concedes that in outright qualifying pace Red Bull hold an advantage that McLaren need to try and close.

"At the moment it doesn't look like we're as quick as the Red Bulls, but it's only practice," he told Rachel.

"Our race pace feels good, forgetting the lap times, our consistency feels good. There is still more work needed to fight with the Red Bulls here but I think we're going in the right direction."

With the little-used Korean International Circuit proving incredibly dusty for the start of the opening day's running, the track condition steadily evolved during practice. However, Button is not expecting too much further improvement.

"I think it's done most of it [evolving]," he said.

"Today it's really improved a lot. As long as we don't have rain or strong winds I think it's not going to reset tomorrow. So today's information is very useful for the weekend."

Sky Sports F1's Ted Kravitz suspected McLaren's strong race pace relative to Red Bull may have come as something of a surprise to Button given the situation just days ago in Japan.

However, he admitted that the situation was more of a concern for the other McLaren heading into Saturday.

"I wonder if Jenson even surprised himself because I said to him 'how did your race pace go' and he said 'yes, it was good. Very promising for Sunday'," Ted told Sky Sports News.

"But it was a real tale of two fortunes at McLaren because with the same car with the same tyres Hamilton was off the pace and in trouble with managing his tyres.

"When he finished for the day he got his gloves off and was out of the car as quick as a flash just wanting to get out and have an understanding from his engineers what had gone wrong because he wasn't as happy in the car. His tyres were going off and he just wasn't as fast as Jenson Button plain and simple."