A dejected Rafael Nadal said he had no choice but to retire from his US Open semi-final against Juan Martín del Potro, as his injured right knee was causing him too much pain. Three days on from his epic five-set victory over Dominic Thiem, the world number one's title defence came to a heartbreaking end as he called a halt to his contest while trailing Del Potro 7-6 [7-3] 6-2.
Nadal's knee playing up
The opening set went to a tie-break on Arthur Ashe Stadium, but Nadal took a medical timeout early in the second – having already had his troublesome knee taped in the first – and his movement was clearly limited thereafter.
In a news conference on Friday, Nadal said: "I had some issues during the tournament. As everybody knows, I had an issue, it was in the second or third match. Then I think was little bit better. I think it was two-all in the first, 15-love, something like this, that I felt [something]. I said to my box immediately that I felt something on the knee. After that, I was just trying to see if in some moment the thing can improve during the match. But no, it was not the day. I waited as much as I can. You could imagine [it was] very difficult for me to say goodbye before the match finished. But at some point you have to take a decision. It was so difficult for me to keep playing at the same time that way, having too much pain. That was not a tennis match at the end, no? It was just one player playing, the other one staying on the other side of the court. I hate to retire, but staying one more set out there playing like this will be too much for me."
Asked whether his five-setter with Thiem may have had an impact on his knee, Nadal replied: "You never know. Maybe zero, maybe yes. I was not feeling the worst of my knee today before the match or yesterday when I practiced."
Knee trouble is nothing new for Nadal, who was also forced to retire in the quarter-finals of this year's Australian Open due to a hip problem. "I'm having two great years. Last year was a fantastic year. This year has been a fantastic year until this moment," he insisted. "I lost four matches. Two of them I had to retire. The negative thing is two of them have been in the quarter-finals and semi-finals of a grand slam, close to fight for titles. That's frustrating. It is tough for me. At the same time, on the other hand, I am going to keep going and keep working hard to keep having opportunities. I know things are going the right way. I am playing well. I am enjoying [being] on court. I am having a lot of success. I am very competitive at the age of 32. Lots of people in this room, including myself, never will think [sic] that at the age of 32 I will be here fighting for titles, fighting for the first position of the rankings."