Andy Murray says veteran Spaniard David Ferrer has inspired him to believe he can play long into his thirties.

Murray, who turns 29 in May, will go up against the 33-year-old Ferrer in the Australian Open quarter-finals on Wednesday and the Scot will be favourite, having won all of their last five meetings.

Ferrer, however, is a tireless opponent, relentless in his work ethic and still considered one of the fittest players on the tour.

He may lack the weapons routinely needed to win a major tournament - he has reached four major semi-finals and one final in his career - but his consistency at the top of the men's game makes him a serious proposition for the British number one.

It is 277 weeks since Ferrer was last ranked outside the top 10 and 340 since he was not in the top 20. In his last 22 grand slams, only three times has he failed to make the second week.

And the world number eight's durability amongst the elite is all the more impressive given it has extended long into the twilight years of his career, when many players either accept a dwindling of their talents or retire from the game completely.

Lleyton Hewitt, only a year older at 34, bowed out to great fanfare on Rod Laver Arena last week, having reached one major quarter-final since 2007.

But Ferrer, along with Roger Federer who is 34, appears to have paved the way, with five of the world's current top 10 aged 30 or older, and only one - Japan's Kei Nishikori - younger than 28.

"Roger's in kind of the same position as David, both of them have been around the game for a long, long time and been up at the top," Murray said.

"The more players that do that, I think the more other players look at it and go, actually, you know, I can do that as well.

"You don't have to retire when you're 31 now or when you're 32. As long as you still have the passion and dedication to work hard, and obviously if you can stay injury-free, it's possible.

"Even Feliciano Lopez, he's 35 this year too. There's a lot of guys that seem to be playing a little bit longer now. All it comes down to is really the body and your passion."

Murray beat Ferrer fairly comfortably in four sets at the same stage of the French Open last year but the world number two is yet to find his best form in Melbourne.

He admits off-court issues, including the collapse of his father-in-law Nigel Sears on Saturday, as well as the imminent arrival of his first child next month, have taken their toll, which could make Ferrer's never-say-die attitude all the more exhausting.

If the Briton finds anything near top gear, however, he should go through.

"He obviously works extremely hard. He's in good shape. He fights so hard in every single match," Murray said.

"He's been rewarded for that with an unbelievably consistent career at the top of the game.

"This year he's made some changes to his racket as well, which would suggest that he's still trying to improve and trying to learn and do different things as well. All credit to him."