He said that tennis tended to fly under the radar when the issue of government backing surfaced.
"The grand prix looks expensive but so is the tennis," Walker said.
"We've never had the debate about the tennis before. They have committed another $368 million to keep it until 2036.
"There's already $1 billion been spent down there but people don't talk about that."
According to Walker, tennis' worldwide television audience were mainly cable viewers while the F1 race was on free-to-air TV in many countries.
He said the decision whether to bid for an extension for the race beyond 2015 was "entirely" up to Victorian Premier Ted Baillieu.
"If he thinks it's good for the state he'll renew it, if he doesn't he won't," he said.
But he said the government understood the importance of the grand prix in attracting the attention needed to bring even bigger events to Australia.
"If you lose the grand prix you'll never get something back of that size for 20 years.
"We'll never see another Olympics, we'll never see another Commonwealth Games, we won't see World Cup soccer."
- AAP