The Spaniard, who won the tournament in 2009 and missed last year's opening Grand Slam through injury, faces a testing first round encounter against the world number 52 on Monday.
Rafael Nadal hits a return during a practice session in Melbourne. Pic/AFP.
Tomic was due to play Ukraine's Sergiy Stakhovsky in the Sydney International semi-finals later Friday in the defence of his title. In the draw made in Melbourne on Friday, Nadal was seeded to face Argentine fifth seed Juan Martin del Potro in the quarters.
Serbia's world number two Novak Djokovic, bidding for his fifth Australian crown and fourth in a row, was drawn to face Swiss Stanislas Wawrinka in the last eight. Djokovic must first play Slovakia's Lukas Lacko in the opening round in the bottom half of the men's draw.
Britain's three-time runner-up Andy Murray was seeded to face 17-time Grand Slam champion Roger Federer in the quarter-finals in the top half of the draw. Wimbledon champion Murray will play Japan's Go Soeda first-up. Federer, a four-time winner in Melbourne, meets Australian wild card James Duckworth in the opening round and could face Frenchman Jo-Wilfried Tsonga in the fourth round.
Spanish third seed David Ferrer was drawn to face Czech seventh seed Tomas Berdych in the other quarter-final.
Unseeded Australian Lleyton Hewitt was in Nadal's side of the draw and faces Italian 24th seed Andreas Seppi in the first round.
In the women's draw, world number one Serena Williams faces a potential semi-final with China's Li Na. Williams, who could equal Martina Navratilova and Chris Evert's total of 18 Grand Slam singles titles with victory at Melbourne Park, will play Australian Ashleigh Barty first up. The American, a five-time Australian Open champion, is seeded to face Italy's seventh seed Sara Errani in the quarters before a potential semi-final clash with fourth-seeded Li.
Li, who lost to Victoria Azarenka in last year's final, is drawn to face Czech left-hander Petra Kvitova in the last eight. Two-time defending champion and world number two Azarenka will play Sweden's Johanna Larsson in the opening round and has a potential quarter-final with Polish fifth seed Agnieszka Radwanska.
Russian third seed Maria Sharapova, a winner in Melbourne in 2008, faces a tough opening round against American Bethanie Mattek-Sands. Mattek-Sands upset top seed Radwanska at this week's Sydney International, but later withdrew from the tournament with back trouble. Sharapova was seeded to face Serbian eight seed Jelena Jankovic in the quarter-finals.