Speaking ahead of his appearance in the year-opening tournament, the Qatar Open which starts on New Year’s Day, the world number 19 said men’s tennis was set for a “very interesting year”.
Since 2010 28 of 32 Grand Slam titles were won by the quartet.
Asked if the ‘big four era was over, the Czech Republic star responded: ” It’s hard to say right now. But yes, I think it’s very possible.
“I’m not saying that it’s over, but I think it’s the nature of the process of the time and of the sport.”
He added that he expected other players emerging through the year to “be definitely competitive to get a chance to win a Slam”.
The 32-year-old was speaking after the late withdrawal from the tournament of defending champion Djokovic, who has an elbow injury.
Combined with the continued injury concerns of Nadal, still recuperating from a knee problem, Murray recovering from a hip issue, as well as Federer turning 37 in 2018, the door seems open for new stars to stake their claim next year.
It’s time! ⏲ Thiem, Berdych kick off the 2018 Qatar ExxonMobil Open in Doha. 🙌🏼 🎉 🎆
— ATP World Tour (@ATPWorldTour) December 31, 2017
And Berdych, 32, once a world number four, says he still harbours hope of winning a Grand Slam.
“I think that’s the beauty of our sport that no matter where you are, you still have a big chance.
It’s about that particular day, and from that one day you can create a great week.
“From one great week, you can make it two and that’s what you are looking for.
“To be honest, that’s the only reason why I’m still around.”
A semi-finalist in the past two years in Doha and seeded three this time round, he begins his quest for the title against Germany’s Jan-Lennard Struff.
The top seed in Doha is Austria’s Dominic Thiem, who begins his campaign against Evgeny Donskoy of Russia.
Former world number one Andy Murray said Sunday he was desperate to get back into competitive tennis after a five-month absence due to a debilitating hip injury.
Murray, who is in Queensland for the season-opening Brisbane International, has not played on the ATP tour since losing a tough five-setter to American Sam Querrey in the quarter-finals at Wimbledon.
He said despite some lingering problems with his hip, his body was feeling much better than at the same stage last year.
“I don’t feel like there’s many miles in my legs, which, you know, was certainly the case at the beginning of 2017, where most days I was quite sore kind of all over,” he said.
“Right now the hip is the only thing that is any concern. The rest of my body feels really good.”
Murray admitted he wasn’t heading into this tournament or the Australian Open with great expectations.
“Just because I’ve not played for such a long time,” he said.
“And also I just want to enjoy playing again. I’ve really missed it the last six months or so.
“I don’t mind if it is at 30 in the world. I would love to be number one in the world, but I just want to play.”
Murray spent 41 weeks at number one, losing that ranking in August during his injury-enforced absence.
He is now ranked 16th in the world and said he had adjusted his schedule to play less in 2018 in a bid to avoid further injury.
“Certainly, when you miss a period, you realise how lucky you are to be doing this as a job,” he said.
“Giving yourself breaks, especially as you start to get older, I think, is very important and something that I’ll certainly be looking to do for however long I keep playing.
“For tennis as a sport, it’s not good when so many of the top players are injured and for extended periods,” he added.
“I certainly think it’s something that should be looked at and to understand why, what the reason for that is.”
World number four Alexander Zverev is striving to put himself in the best possible position to claim his maiden Grand Slam title in 2018 and the German won't rest until he's done just that.
Following a breakthrough year, in which the 20-year-old won five tournaments, broke into the top-10 for the first time and finished 2017 by making ATP Finals debut in London, Zverev is the undisputed leader of the pack when it comes to the NextGen stars.
And for Zverev, winning the Australian Open in Melbourne is firmly in his sights.
“This is the reason I think I play, this is the reason why I think most tennis players play... to compete and win at the biggest stages. Obviously, for us, the Grand Slams are, and that's what every little kid dreams about, playing those. Once you play them you wanna win them,” Zverev told assembled media ahead of his participation in the Hopman Cup in Perth.
“It's been a bit of a change in the last two years, when I came here before and I was 80 something in the world and now I'm number four. I'm happy with my improvement and the way I've kinda progressed but at the same time I don't wanna stop here. This is not the goals reached yet.”