Marin Cilic advanced to the semi-finals after top seed Rafael Nadal retired hurt. Credit:AP He added: "It's a negative thing, but I [am not] going to complain because [it] happened to me more than others. But on other hand, I was winning more than almost anyone. That's the real thing. But who knows, if I didn't have all these injuries." According to the ATP, Nadal has retired from matches eight times during his career but only twice in Grand Slam matches. They were both at the Australian Open - against Cilic and eight years ago in a quarter-final against Andy Murray. Nadal was uncertain when the injury struck him but thinks it was when he ran for a drop shot in the fourth set and felt pain high in his right leg. He said afterwards it was not his hip. He had treatment from the physio twice and tried to crunch the joint to release tension in the leg. "It is difficult to know exactly what it is now. Is difficult to know exactly the muscle. Just happened minutes ago. This type of injury is difficult to know immediately, no? We need to wait a couple of hours. Tomorrow I am going to do a test, an MRI here, then we will know," he said.

Nadal blamed the heavy schedule on hard courts for leading to injuries against high-profile players. Credit:Alex Ellinghausen Nadal retired when down a break 0-2 in the fifth set and confronting the reality there was no hope he could fight back to win the game when he was limping so badly that he was struggling to walk. "It is not the first time an opportunity that is gone for me. I am a positive person, and I can be positive, but today is an opportunity lost to be in the semi-finals of a Grand Slam and fight for an important title for me. Cilic had previously won just one set against Nadal. Credit:Alex Ellinghausen "In this tournament [it] already happened a couple of times in my life, so it's really, I don't want to say frustration, but [it] is really tough to accept, especially after a tough December that I had without having a chance to start in Abu Dhabi and then Brisbane.

"I worked hard to be here. We did all the things that we believed were the right things to do to be ready. I think I was ready. I was playing okay." Nadal comfortably took the first set against the sixth seed Cilic, who had not beaten him in the last seven matches. Over nine years Cilic had won just one set against Nadal. Then he won four games in a row and took the second set on Tuesday. Cilic hit an astonishing 83 winners. He hit 20 aces to Nadal's three. He constantly pushed sliding balls out wide to Nadal in the deuce court. Repeatedly he won points, so he just kept doing it. Variety be damned. "He was playing good... but I was fighting for it. I was two sets to one up," Nadal said. When a similar argument was raised about injuries last year, the world No. 1's position received little support from rival Roger Federer.

"Shave 10 years off our age, and we probably will do better," Federer said in November last year at the ATP World Tour finals when asked about another Nadal injury. "A lot of the guys are just touching 30 plus. Back in the day, at 30, a lot of guys were retiring. Edberg, Sampras, it was, like, normal at 29, 32, to start looking towards the end of your career. Now you guys expect everybody to play till 36. "When somebody is injured at 31, it's like, 'Oh, my God, how is this possible?' Actually, it's a normal thing. "If either you retire or you take a sufficient break so when you do come back you maybe have another few years left again because you really made sure your rehab is good. So I think for the most part it's age, coincidence. "The season has been the same for many, many years, as we know. I think just when you get older, you maybe have to manage your schedule maybe a little bit differently.

Loading "But some guys, they just go maybe all out for 15 years, and they do it until you sort of break down, then you just reset." Cilic will play unseeded British player Kyle Edmund in the semi-final. A week ago you would not have given counterfeit money on that happening.