Melbourne - Retired two-time Grand Slam champion Li Na believes Serena Williams will be untouchable at the Australian Open and doesn't expect her to quit even if she surpasses Margaret Court's record 24 Grand Slam titles.
Williams is gunning to equal Steffi Graf's Open-era record of 22 Slams in Melbourne, but has been battling fitness concerns early in the season.
But Chinese superstar Li, who made three Australian Open finals before finally winning in 2014, said few can touch Williams if she has her mind set on winning.
"If Serena Williams wants to win, she can win," Li told The Australian newspaper Monday, before Williams won her opening match 6-4, 7-5 against Italy's Camila Giorgi.
Williams dropped only three matches in 56 last season and won three majors: the Australian and French Opens and Wimbledon, before being deprived of a calendar-year Grand Slam at Flushing Meadows.
Even if the world number one, now 34, equals Graf's Open-era record and goes on to beat Court's all-time mark, Li does not expect her to retire.
"With the way she is playing right now, I don't think so," said Li, adding that the American remains an imposing sight across the net.
"I don't know about other players, but for myself, I really loved to play against Serena because it was a real challenge for myself," said the popular Li, who retired in 2014 to settle down and have children.
"I always look forward to playing against tough players because before the match starts you never know what will happen, right?"
Li, an Asian trailblazer whose feats sparked a surge in tennis's popularity across the region, said she missed being on tour but was content with her new life outside tennis.
"I miss the fight, competition (of tennis) because in the normal life you really don't have much chance for that," she said.
"But I really love the way I have life right now because I will put a lot of teaching time for my baby."