Leon Smith: Andy Murray strong form a factor in French Open struggles

Andy Murray's superb form going into the French Open could be a factor in his struggles at Roland Garros, according to Great Britain Davis Cup captain Leon Smith.

The world number two arrived in Paris on a five-match winning streak after comprehensively beating Novak Djokovic in the final of the Masters event in Rome.

He has the best winning percentage on clay, formerly his weakest surface, of anyone over the past 13 months, making his difficulties during the first two rounds even more perplexing.

Against Radek Stepanek and Mathias Bourgue, ranked 128 and 164 respectively, Murray has twice been taken to five sets and needed more than seven hours to battle his way into the third round.

Smith, Murray's childhood coach and a close friend, is coaching British number two Aljaz Bedene in Paris but has been in Murray's box for both matches.

He dismissed suggestions additional pressure on Murray this year was playing on his mind - "h e expects to win every year, not just this year" - but accepted the Rome performance against Djokovic in particular may have had an impact.

Smith told Press Association Sport: " Clearly the form he's showed in Monte Carlo, Madrid and of course in Rome with Djokovic, it got everyone talking about it a bit more and I'm sure, with the standards he's set, how he was hitting the ball, how he was executing every point and rally, it was exceptional.

"Then if it doesn't quite go that way in the early rounds here, there's a bit of frustration, which I think is pretty normal, because he set himself an unbelievable last match against Novak Djokovic and then suddenly the timing's not quite there.

"Of course he'll be a bit frustrated, but that's what happens in this crazy sport. It literally changes every single day - yourself, the opponent, the conditions."

The main concern for Murray is the emotional and physical toll the two matches will have taken on him, with five more to come if he is to win the title for the first time.

No player in the Open era has won a grand slam having played more than three five-set matches in a single tournament.

Next up for Murray on Friday is 6ft 11in Ivo Karlovic, who is likely also to be feeling weary after finally overcoming Australia's Jordan Thompson 12-10 in the fifth set in round two.

Karlovic plays a serve-and-volley game so Murray at least should not be drawn into too many long rallies.

Smith said: "It's tough for Andy because ideally he'd obviously want to get through the first two rounds a lot quicker but it's not been that way. But the important thing is he's won.

"Both those matches, you can lose those, the tournament's over for a year and it's finished. He's still in the draw, even though it's not ideal, and hopefully he can use the rest day to recover as best he can.

"The best scenario now is that he goes out and beats Karlovic in as straightforward fashion as he can, but that's a tough ask because of the way Karlovic plays. There's likely to be tie-breaks but let's hope he can get through that one."

Another factor may have been the discussion over Murray's split from former coach Amelie Mauresmo, which was sparked back into life at the weekend by an interview the Frenchwoman gave l'Equipe.

In it, she described her form charge as complex and hinted his on-court behaviour played a part in the end of their partnership, although that was flatly denied by Murray.

The 29-year-old said after his win over Stepanek the previous few days had been "difficult" and was keen to point out the positive side of his emotional nature.

That has certainly been in evidence this week, with Murray digging deep into his seemingly never-ending well of fighting spirit.

"I showed a lot of heart the last few days in tough, tough matches, a tough atmosphere (against Bourgue)," he said. "Maybe not feeling or playing my best, but I found a way to win."

At 37, Karlovic is the oldest man to make the third round of a slam since Jimmy Connors at the US Open in 1991.

"It's the only time when being old is okay," he said with a smile.

"It's unbelievable because this year I was struggling with the injury, with the knee. So I was out for two months almost. So this is really unbelievable for me."

The pair have met six times before with Murray winning on each occasion.

Their last match came in the fourth round of Wimbledon last year, when the Scot dropped the third set but triumphed in four. Right now, he would probably settle for that.