MELBOURNE, Jan 23 (Reuters) - World ‌number one Aryna Sabalenka has been impressed by the longevity of Novak Djokovic and others ‌on the men's tour and hopes one day to be the "grandma" of the women's ‌game.

The Belarusian has already banked four Grand Slam titles at the age of 27 and is favourite for a third crown at the Australian Open where she reached the fourth round for the sixth consecutive time on Friday.