ANDY MURRAY knows the era of the ‘Big Four’ may soon come to an end – but he’s determined to extend his stay at the summit of world tennis for a few more years yet.

These are unprecedented times in this sport, a golden era that many may only really appreciate when it’s over.

Between them Murray, Roger Federer, Rafael Nadal and Novak Djokovic have won 35 of the last 37 Grand Slam titles, won an accumulative £136 million in prize money and Wimbledon legend Bjorn Borg believes the gap between the quartet and the rest remains as large as ever.

But Murray, who takes on Grigor Dimitrov in today’s Wimbledon quarter-finals, believes others are starting to make an impact.

“Often Roger and Rafa played in the finals of slams, Novak obviously made his mark, and then over the last couple of years I’ve managed to get to a few,” he said.

“If you have the top players playing well at the biggest events, that makes it interesting. I think people like to see that and it’s great for the sport to have those rivalries.

“The only way to have the consistency you are seeing is to work hard all the time. That’s it, you can’t get away from that. If you spend a few months not working hard, the results will show.

“It’s such a tough sport now. It’s physically very demanding, especially in the slams and the big events. My only advice to any young player coming through is to work hard and try to get the most out of your game, because if not, you’re going to look back with some regrets.

“I’m sure guys like Dimitrov will soon start playing in the latter stages of events and it’s important to have that consistency for the fans.”

Murray has been called many things at Wimbledon but probably never a ‘dude’, the label given him by today’s rival Dimitrov.

On paper, this should be another straight forward test for a player who is now unbeaten in 17 matches at the All England Club, a run dating back to his gold medal triumph at the London 2012 Olympics.

He’s dropped no sets, his serve has barely been threatened, his march has been relentless.

But Wimbledon fans will remember saying something very similar about Pete Sampras and the defence of his title in 2001 – and he was beaten by a young upstart called Roger Federer in the fourth round.

Murray has won three of his four encounters with the world number 13, with all their previous matches played on hard courts.

However, he did lose their most recent clash, going down in three tight sets over three hours in Acapulco earlier this year.

Dimitrov went on to win that tournament, arguably the biggest win of his career, in a final against Kevin Anderson, the player Murray defeated in the fourth round.

And he also the most accomplished grass court player Murray has encountered yet. He’s a former Junior Wimbledon winner – the best Murray achieved in that event was reaching the third round – and last month succeeded the Scot as Queen’s Club champion.

“He’s a more mature player now,” said Murray. “Watching him play, technically he hasn’t made many changes to his game but he’s playing higher percentage tennis and making better decisions. That adds up to winning many more matches.”

Dimitrov is used to answering questions about his relationship with Maria Sharapova – but attention now turns to his fledgling bromance with Murray.

“He’s a cool dude, I think we get along pretty good but it’s one thing is off the court, other thing is on the court,” he said.