World number one Nadal, meanwhile, has been granted what appears to be a relatively simple route into the latter stages of the tournament, but only if last year's beaten finalist can prove his fitness following recent knee problems of his own.
Can the new generation stop Federer?
Maria Sharapova [16.0] will get plenty of attention, after re-entering the top 50 for the first time since her ban. "For me, that's more the issue".
Zverev, 20, won five tournaments last year, including Masters 1000 events in Rome and Montreal, to announce himself as a force to be reckoned with. "To me, he's the clear favourite".
"My wife in September gave birth to our second child and I could be there with her and with our children spend five months without separating". If healthy this season - a big if for Djokovic and Nadal as it begins - they still look like the stars around which others will orbit.
Seven-time champion Williams announced last week she wouldn't defend her title, saying she was "super close" but not quite ready to compete so soon after becoming a mother.
Nadal, who pulled out of his first ATP Tour event of the year but appeared at an exhibition match, starts his Australian campaign against the 83rd-ranked Victor Estrella Burgos of the Dominican Republic.
Should he succeed, Federer will move onto six Australian Open crowns - the joint highest tally of any man alongside Djokovic and Roy Emerson.
"When you see those type of opportunities, you need to be able to seize them", he said.
Andy Murray has had to extend his six-month absence by having hip surgery, while Novak Djokovic and Stan Wawrinka have not played competitively since Wimbledon in July although the pair, unlike the Briton, will be at Melbourne Park.
Williams remains, at 23 Grand Slam singles titles, one short of Court's record. He withdrew from the 2017 ATP Finals in London due to a right knee injury.
Court, a Pentecostal pastor, has strong views on homosexuality.