By Alix Ramsay

This, we are told, is the golden age of tennis; we have never had it so good. When Andy Murray reached his first major final back in 2008, he was finally allowed into the elite club at the top of the rankings, the Gang of Four who formed a closed shop at the sharp end of every grand slam tournament.

When he started winning the big titles in 2012, Murray was given full membership to that club and the gulf between them and the rest of the field was wider than ever. But as this season unfolds, it would appear that the gold leaf is beginning to peel just a little from this golden age. The results of the past few days at Wimbledon have not only marked a potential change in the pecking order but they have also served as a warning to the big boys.

As they tried to carve up the final rounds in SW19, Novak Djokovic had not won a major title in 18 months, Roger Federer had not won one in two years, Murray had not reached a final of any description since winning Wimbledon last year and Rafa Nadal had only won five matches on a grass court since losing the 2011 Wimbledon final to Djokovic. As we move into the semifinals, only Federer and Djokovic remain.

That is not to say the Big Four are dead in the water: until Stan Wawrinka won the Australian Open in January – and only did so because Nadal’s back had seized up in the warm-up – the foursome had won the last 16 consecutive grand slam titles. But the upsets and shocks in SW19 have proved that the establishment needs to be on its guard: the young blokes are champing at the bit for their chance to take over at the top. Nick Kyrgios showed that by beating Nadal on Tuesday and Grigor Dimitrov stated his intent by thrashing Murray 6-1, 7-6, 6-2 in the quarterfinals on Wednesday. Milos Raonic, another of the new wave, then did for Kyrgios and took his place in the semi-finals and started planning his tactics for Friday and his showdown with Federer.

It was Murray’s worst result at Wimbledon since 2008 (he has been in three semifinals and two finals since Rafa clumped him back then) and it was his worst performance at a grand slam since he froze in the Australian Open final in 2011. But at least then, against Djokovic, he played a bit; against the young and eager Dimitrov he could not do anything right. No part of his game was working and he looked as flat as a pancake. Dimitrov, by contrast was running away with the victory and all the way through to his first major semifinal. He was a cool as can be while Murray just looked lost.

“He was the better player from start to finish,” Murray said and nobody was willing to put up an argument.

Having spent the past six years with his eyes fixed on the big blokes ahead of him, his fellow elite club members, he now has to keep looking over his shoulder to watch out for the younger lads who are rapidly gaining ground on him and the rest of the Gang of Four. Murray’s immediate priority is to make sure he does not get trampled in that changing of the guard.

At least Murray is alert to the situation and, as is his way, he believes that nothing short of back-breaking work is the answer. Since winning in SW19 last year, his year has been interrupted by back surgery, a three-month recovery period and then a slow and frustrating comeback to full fitness and some semblance of form. He thought he had achieved that when he whistled through the first week of The Championships unscathed and barely broke a sweat. And the Dimitrov pulled him up short.

“I don’t feel like I have improved so much since Wimbledon last year,” he said. “I think I’ve played some very good tennis but also some ordinary stuff at times. If you play against a player like a Kyrgios or Dimitrov or Raonic and those guys and you don’t play very well, it’s tough to win those matches now; whereas before maybe when they’re younger and a bit inexperienced you can still find ways to come through them. But now that they’re getting more experience and improving, it’s tough to do that.

“For me this year, coming back from the surgery, I haven’t had as much time training as I would have liked.  I was always trying to get matches in and get match‑sharp, as well. But, look, I played very well the first, what, four matches. I played very good tennis. I played a high level. Then today wasn’t like that, so it’s disappointing. But I feel like if I hit the ball, struck the ball like I had done against Anderson in the round before, the match could have been a lot closer than it was.”

Who will help him makes those improvements remains to be seen. Amelie Mauresmo has not yet committed to Project Murray – she will sit down with Scotland’s finest in the next few days and decide whether she will continue as his coach and, if she does, what the structure of that arrangement will be. If she decides not to take the fulltime job in Murray’s team, the Scot will be back to square one and looking for a regular replacement for Ivan Lendl.

Lendl gave him the key to grand slam success: he showed Murray how to win the major finals. Now he needs someone to show him how to build a long and successful career at the top, how to win many grand slam titles while, at the same time, improving with every season to keep one step ahead of the young talent behind him. Whether Lendl could have taken his charge on to the next level, we will never know and whether Mauresmo wants to stick around to try, we will soon find out.

Murray knows that something needs to be done and done soon. He cannot afford to suffer another flat day and heavy defeat at another grand slam – if he does, the young men will think he is there for the taking.

“I need to make some improvements in my game,” he said. “I need to get on the practice court soon, because now there’s time before the next bunch of tournaments to do that, to make improvements. It’s not often in the year you get that much time.

“But I’ll also need to have a think for a few days about how it is I’m going to go about that, how it is I’m going to go about improving and trying to get better again. I’ll definitely take a few days away from the court. I’ll then start practicing fairly soon.

Murray is a bright man and once he has worked out exactly what he wants to do and with whom, he can get to work. But he needs to work fast. The golden age may not be over yet but its shelf-life is limited and Murray needs to make sure he is back in the winning groove before his sell-by date expires.