Andy Murray is 'suffering' - Rafael Nadal

The former world number one’s impending retirement was a decision he needed to take because he is "suffering", says long-time rival Rafael Nadal.

The 31-year-old Andy Murray announced on Friday that he will quit this year, and probably next week's Australian Open could be the final tournament of his career.

"When you are going on court without a clear goal because you cannot move well and you have pain, then it is the time to take a decision," Nadal said.

“It seems like he had not a very long career because today players are playing that long. But 10 years ago, if he retired at 31, we would say he had a great and very long career”

Rafael Nadal on Andy Murray

"He will be a big loss for tennis."

The 32-year-old Nadal knows more than most tennis players what it is like to battle injury having had a catalogue of serious problems over the years, particularly with his knees and wrists.

But the 17-time Grand Slam singles champion Nadal says he has never "arrived" at the point of feeling he had to quit tennis. 

"I always had the feeling that we'll fix it," said Nadal. The world number two will begin his Australian Open campaign against home wildcard James Duckworth on Monday.

"But, of course, there are periods of time that you don't see the light. It is tough.”

"I know it is hard mentally. It is tough when you have one thing, then another thing.”

"Andy has probably been fighting to keep going for a long time. If he doesn't feel that the injury can become better, he has probably done the right thing for his mental health."

Scotland's Murray first encounter with Nadal was when they were teenagers and played against each other at junior tournaments. 

As seniors, the pair have met 24 times, with the Majorcan winning 17 of the contests.

"I always had good relationship with him," said Nadal. "We shared moments in my academy.

“We shared courts in the most important stadiums in the world, competing for the most important things. That's impossible to forget.”

"So all the best to him. We will miss him. But today is him. Tomorrow another one. We are not 20 any more. Our generation, everyone is more than 30 - these kind of things happen.”

"He will be a very important loss for us, for the world of tennis, for the tour, for the fans. But that's life. It seems like he had not a very long career because today players are playing that long. But he's 31 - 10 years ago, if he retired at 31, we would say he had a great and very long career."