Stan Wawrinka is aware it will be a very different Andy Murray he faces in the French Open semi-finals on Friday than the one he has bullied on clay in the past.
In three previous meetings on the surface, Murray has not won a set, but the last of those came in Monte Carlo in 2013, before the Scot turned himself into one of the world's best clay-courters.
It is the fourth time Murray has made the last four and the first time he does not have to face either Rafael Nadal or Novak Djokovic, but Wawrinka is hardly a step down.
The Swiss played the match of his life against Djokovic to win the title 12 months ago and is on a 12-match winning streak at Roland Garros.
Wawrinka said of his opponent: "W e didn't play that much the last few years. I played him in London (at the O2) last year. That's it.
"On clay, it's been a long time. He improved a lot. He's playing so well, especially again if you look this year. He won Rome, final in Madrid, semi-final in Monaco.
"So it's going to be an interesting match, for sure. We normally play some good battles in the past, so I'm quite happy to play him. I think it's going to be a great challenge and a great semi-final."
Wawrinka is not surprised by Murray's improvement, saying: " I think even before, when he wasn't a clay-court player, he was making the semi-final here.
"I think he's an amazing player since many, many years. He always tries to improve his game, always tries to be a better player. The way he improved on clay is quite impressive, because now he's winning a lot of tournaments and big titles."
Murray has not won a set against Wawrinka since 2012 and cannot afford to make as many errors as he did in the opening two sets of his quarter-final against Richard Gasquet.
The world number two partly attributed that to having to adjust his game having played big servers Ivo Karlovic and John Isner in rounds three and four.
It could be to his advantage, therefore, that both Gasquet and Wawrinka have singled-handed backhands.
"They obviously have some similarities but Stan probably hits a flatter ball," said Murray, who is looking to become the first British finalist in the men's singles here since Bunny Austin in 1937.
"At least I got used to playing against a single-hander who can use the angles, change the direction up the line. So for that it was good preparation, but Stan definitely serves a little bit bigger. He is a tough guy to break when he's serving well."
Novak Djokovic and Dominic Thiem will play for a fourth day in a row in the other semi-final after rain badly affected the top half of the draw.
The women's semi-finals will take place a day later than scheduled, with Serena Williams meeting surprise package Kiki Bertens and Garbine Muguruza facing Sam Stosur.