Hewitt, ranked No. 3 in the world, said no other Aussie player is ranked in the top 100 and that's "not good enough," The Australian reported Thursday.
"Definitely, there need to be changes -- changes made to produce more players, but right at the moment I'm probably not the best guy to ask purely because I haven't seen the whole structure," Hewitt said.
"But you look at the other countries coming through and we just don't have enough depth, it's as simple as that. We have one guy in the top 100."
Hewitt is in his hometown of Adelaide, preparing for 2005's first Grand Slam, the Australian Open, which begins Jan. 17 in Melbourne.
"In the past, we've had more than a few people playing in junior Grand Slams but they haven't been able to make that transition to the seniors and really get a world ranking in the top 150, 100," Hewitt said. "That's where you've got to be on the tour week in, week out."