Fellow Australian Thanasi Kokkinakis was this week awarded a discretionary wildcard.

Tomic currently sits 143 in the world rankings, well below his career best world No.17 in 2016.

It appears Tomic will have to battle it out with a host of no names after being invited to compete in a 16-man field in the wildcard playoff in Melbourne in December.

He is yet to accept the invitation.

"He's had a tough year and he needs matches and he's got to put himself out there on the line to have a crack at making the Open," Hewitt said.

"We all know the kind of tennis he can play but he has to get back to that level and he also needs to commit to the sport as well and we won't be making any more wildcard decisions until we see what happens in the playoffs."

Hewitt was understandably more positive about Nick Kyrgios’ immediate future, saying the Australian Grand Slam’s field was wide open.

"Coming in a lot of the top guys from the previous years are going to be seeded a lot lower because they haven't played really for the last six months so there's going to be a question mark on how they come in and how their bodies are holding up," Hewitt said.

"(Roger) Federer is going to go in as favourite as age 36 but there's going to some opportunities for some young guys to stand up and maybe win a grand slam."