Andy Murray is smiling – a lot and disconcertingly. He doesn't get why people keep asking about it but there is no denying it is there, plastered all over his face, even in the difficult moments he has endured on his way to the quarter-finals of this French Open, where he will meet his eccentric friend, Gael Monfils, today.

Murray has every reason to be pleased. He has endured a searching examination against Andrey Golubev, an easier match against Marinko "Mad Dog" Matosevic and then a five-setter over two days against Philipp Kohlschreiber and a four-setter on Monday when he beat the volcanic Spaniard, Fernando Verdasco.

So, if he needs an excuse to smile, he has several. Most importantly he is finally shredding the emotional and physical baggage of back surgery eight months ago that might have ended his career at its peak. And he is starting to hit the cover off the ball, with a second French semi-final – and probable match against Rafael Nadal – one win away.

“The way I’m hitting my backhand now is 10 times better than it was last year, and moving to that side as well is so much better than it was,” Murray said. “There were periods this year when I had problems but that is to be expected with surgery and it’s starting to get better slowly. I’m close to being back to 100 per cent. That’s exciting for me, especially at this stage of the year with a big few weeks around the corner.”

He added: “I was in a lot of pain for a long time. Daily. It’s frustrating, tiring. You go through a lot of different emotions. At times it can make you very angry because I normally enjoy all the training that goes with it but there were periods when it would become difficult.

“I’d try to push hard and it would hurt, so I’d have to ease off and I couldn’t get myself into the shape I wanted to be in. Hopefully now I’m over the worst and, so long as I keep monitoring it and doing all the right things with it, I’ll be fine.”

Elsewhere in the quarter-finals, things are not so calm. When David Ferrer was asked what he thought about the abdication of the King of Spain, he replied: "Any story has an end. This applies to anyone."

Regal friend

Even the real King of Spain, Rafael Nadal? Maybe not yet. The concern about the other match today is that Ferrer will collapse again in the big moment against his regal friend, who is three wins from a ninth French Open title and has beaten him in 21 of 27 matches, though he has lost two of the past three, including the most recent, in Monte Carlo this summer.

Ferrer is not reading too much into his recent win over Nadal and he dismisses the notion that his friend is suffering with a back problem. Nadal, for his part, was unusually irritable when asked to elaborate on his courtside tics, particularly when arranging his water bottles on the ground in exactly the same pattern. He does not like change (and regretted the abdication of his king, by the way).

Ferrer hopes to do better than in last year’s final. “It was a little bit too much for me. But every year is different.” And, in all likelihood, Nadal’s reign will not be interrupted.

Yesterday, Ernests Gulbis sustained his eye-catching run with a stylish, serve-led demolition of Tomas Berdych that will give the world number two Novak Djokovic plenty to ponder before their semi-final tomorrow.

Berdych won his match 6-3, 6-2, 6-4, but Djokovic made much harder work of beating Milos Raonic, who fought hard all the way to the end of the first two sets then launched a late fightback from 1-5 in the third before the Serb closed it out on his own serve, 7-5, 7-6, 6-4. Guardian Service