World No.2 Rafael Nadal has revealed he almost pulled out of the Australian Open after suffering an unexplained knee injury on Sunday afternoon.
Nadal, who came into the tournament with a shoulder complaint, was sitting in his hotel room when he felt a 'crack' in his knee.
The Spaniard went on to say that he struggled to move his leg and was forced to go to hospital to undergo a series of scans.
After treatment late on Sunday night and early Monday morning, Nadal was able to take to the court where he posted a comfortable 6-4 6-1 6-1 victory over American qualifier Alex Kuznetsov.
"I was sitting on a chair in the hotel. I felt like a crack on the knee, but is nothing really strange. Happens lot of time with articulation, movement, articulation," he said.
"I stand up. I felt the knee a little bit strange. I moved the leg like this two times to try to find the feeling. After the second time, the knee stays with an unbelievable pain completely straight."
"I really couldn't move the knee like this (indicating just a little bit). I have no movement on the knee. I did all the tests. Came here for ultrasound. Went to hospital for MRI."
"And, seriously, yesterday during the evening I wasn't hundred percent sure I would have chance to play, because with the movement of that knee I felt that I will not be able to play."
"I did a lot of treatment. The MRI was positive. Nothing wrong shows the MRI. So that's always a lot of calm."
"Finally what happened is with the movement, articulation, probably pinch maybe the tendon little bit or something that put the tendon completely straight."
"I started the match with a little bit of scare at the beginning and nervous because I was really disappointed yesterday."
"But, you know, after the first 10 games that was scare, I started to play with normal conditions. The best thing is I felt the knee very well. So is something that I really don't understand why happened everything, but I am really happy that today I was ready to play and I played a fantastic match."
Despite the major scare on the eve of the Open, Nadal is confident it won't derail his bid to win the tournament for a second time following his 2009 success.
"I did a lot of physiotherapy with my physio trying to relax everything. Anti-inflammatories, a lot. Local anti-inflammatories," he said.
"But I understand when the knee comes back to the right place, you know, and we are able to relax that. So I was much more scared about the first match than the rest, because today now I have 48 hours to the next match."
"So I am really confident that having the worst feeling that I ever had in my knee yesterday and today was able to play. I have fantastic hope that gonna happen the same for after tomorrow."