Djokovic and Murray started the year as the top two ranked players, but poor performances along with injuries saw them drop in the rankings and eventually take time off after both last featured at Wimbledon in July.
Meanwhile, Nadal and Federer have benefited from the duo's absence in 2017 as they split the four Grand Slams between themselves. They have won a combined 13 titles and currently share the top two places in the rankings.
More than anything, it was the longtime rivals having an extended period of rest before making their returns in January earlier this year that saw them both enjoy a career renaissance.
Djokovic and Murray are set to follow suit with many predicting similar results for the duo upon their return, however, Moya, who coaches Nadal, has warned them that it is not as easy it seems.
"You never know what will happen," Moya told Mundo Deportivo via UbiTennis. "They (Nadal and Federer) have done it both, who are two greats of the sport, but it will not be as easy as it may seem."
While it remains to be seen as to whether the pair can emulate Nadal and Federer, Moya is happy that they will be returning soon.
In addition, the likes of Stan Wawrinka, Kei Nishikori, Milos Raonic and Tomas Berdych will also be making their injury comebacks for the new season, making the beginning of 2018 a mouth-watering prospect.
"The fact that they [Djokovic and Murray] will return is going to be good for tennis and for the spectator." Moya added.
"The more players there are with options to win the important tournaments, the better for everyone."