It’s difficult to imagine a world without Roger Federer and Rafael Nadal dominating the highest level of tennis.

Since becoming professionals in 1998 and 2001 respectively, the pair have won a staggering 35 Grand Slam trophies between them.

Federer and Nadal have remained at the top of the sport for much of the last two decades and if 2017 is anything to go by, they’ll be hanging around for a while yet.

The stunning year both men have enjoyed is all the more remarkable coming off the back of hugely testing periods involving injuries and poor form.

With seven titles for Federer and six for Nadal, the worst of their troubles now seems to be well and truly behind them.

The changing of the guard at the top of the men’s game might be some way off, though that doesn’t mean tennis isn’t on the verge of other significant changes.

A series of major rules changes are being trialled at the Next Gen ATP Finals in Milan with a view to introducing them across the entire sport.

Intending to attract new and younger fans with a faster and more TV-friendly product, they include shorter warm-ups, a 25-second shot clock between points, no line judges and first-to-four-games (tie-break at 3-3) sets.

FEDERER WEIGHS IN

Asked for his take on the proposed overhaul to the traditional format, Federer said, per Yahoo Sport: "We need to think, take seriously all these rule changes if ever you're going to do it because once you do it you don't want to bounce back and forth with changing something and then you don't like it later on.

"I don't see that much wrong with our tour right now that it needs that much fixing, especially the shorter sets. I know it can be somewhat intriguing but at the same time the longer sets allow you to stretch a lead, it's more comfortable at times.

"You can try different things. You can work on stuff, whereas if every point counts so much... there's no room for anything anymore. There are positives and negatives to it but I don't want to see anything change on the Tour that much to be honest," the Swiss ace added.

WHAT DOES NADAL THINK?

The Swiss ace has a fairly level-headed view on the matter as usual. But which side of the fence does his greatest rival sit?

In response to the same question, Nadal said: ”There are a couple of things that I like and a couple of things I don't like but nothing is perfect. We are in a sport where we have a big tradition -- not many changes have been made in all of its history.

"If you asked me 'do you want changes?' I will say 'no'. I am number one in the world, I have achieved a lot of things but if the game needs something to be more attractive for the fans, that's the way that the game will move forward.”

"It's not my job… The people who run the sport have to look around and take the right decisions to make our sport even more interesting than it is today. I'm happy with how it is but maybe in the future you need to do something."

So, it seems both men claim the ATP must balance caution and innovation if the game ever requires a major revamp.

Regardless of whether Federer and Nadal will get to experience any changes on the court, surely their opinions carry huge influence in this debate.

What do you think of the proposed rule changes? Let us know your thoughts in the comments.