Exciting teenager Thanasi Kokkinakis could face either Hewitt or Tomic in the third round.
The 19-year-old, ranked 70 in the world, opens his campaign against in-form 12th-seeded Frenchman Richard Gasquet, who beat him in the Cincinatti Masters last week.
Victory over Gasquet would set up a meeting with Rafael Nadal's Wimbledon conquerer Dustin Brown or Richard Hasse of The Netherlands in the second round.
Big-serving Sam Groth and John Millman are also in the main men's draw.
Groth is up against wily Ukranian Alexandr Dolgopolov with Queensland right-hander Millman facing world No.60 Sergiy Stakhovsky.
In the women's draw, Australian No.1 Sam Stosur - seeded 22 - plays Timea Babos of Hungary with Alja Tomljanovic meeting Karin Knapp of Italy.
Daria Gavrilova has a daunting opening encounter with Maria Sharapova, 26th-seeded Italian Flavia Pennetta is Jarmil Gajdosova's opponent with Casey Dellacqua to face a yet to be determined qualifier.
-AAP