The new breed are coming but Lleyton Hewitt says there's every chance ageless champions Roger Federer and Rafael Nadal will continue to dominate tennis in 2018.
In awe of Roger Federer and Rafael Nadal, retired great Lleyton Hewitt is refusing to discount the prospect of the two tennis titans continuing to defy history in 2018.
At 36 and 31 respectively, Federer and Nadal overcame age and lengthy injury layoffs to split the four grand slams two apiece for the first time in a magically retro 2017 season.
Despite losing all four times to his great rival, including an epic five-set Australian Open final, Nadal edged Federer to snare the year-end No.1 ranking.
Federer settled for being the oldest year-end No.2 in history after a tour-topping seven titles, including an eighth Wimbledon crown - without dropping a set for the first time.
As the owner of one of the most astute minds in tennis, Hewitt was asked on Wednesday if the grand old stagers could continue dominating in 2018.
"You wouldn't think so but I don't know if those two are normal, especially Roger," Hewitt said.
"At his age, he's wound back the clock. Even against Rafa, he's done the best he ever has against him.
"I wouldn't say there's anything those two can't do."
While he's not doubting Federer and Nadal, Hewitt says question marks surround the likelihood of their fellow big-four rivals Novak Djokovic and Andy Murray return from their own injury-enforced breaks.
Neither six-times Australian Open champion Djokovic or five-times Melbourne Park runner-up Murray have played since Wimbledon in July.
Djokovic has slipped to 12th in the world after battling a long-standing elbow injury, while Murray is 16th as he struggles to overcome a chronic hip complaint.
"I don't know if they'll be as dominant as they were," Hewitt said.
"For them to pick up where they left off a couple of years ago is not that easy.
"But I would never right those guys off. They've played so well in Australia in hot conditions and also in night matches on Rod Laver Arena.
"If they can get through that first week and give themselves a chance, then they'll be tough to beat."
With three-time grand slam champion Stan Wawrinka sidelined with a knee injury and several other established top-tenners and former grand slam finalists on the comeback trail, Hewitt hopes Australia's emerging forces Nick Kyrgios, Thanasi Kokkinakis and Jordan Thompson can cause some damage at the Open.
"It's an interesting one," Hewitt said.
"You've got (Stan) Wawrinka, (Milos) Raonic, (Kei) Nishikori - a lot of top guys coming off an extended break from injuries or surgeries at the end of the year.
"So the door is open for some of these younger Aussie boys."