"The offer came a little bit out of the blue," Hughes told the Walsall website.
"It is a once-in-a-lifetime opportunity and I want to give it a go. I've really enjoyed my time at Walsall and will miss the players and staff."
Mark feels this is an opportunity he wants to pursue and we will not stand in his way
Walsall boss Chris Hutchings
Hughes joined the Saddlers from Northampton Town in July 2009 and approached boss Chris Hutchings as soon as he had contact from Australia.
"Mark contacted me late last week regarding the offer," Hutchings said.
"We spoke at length about the move and agreed to go our separate ways. Mark feels this is an opportunity he wants to pursue and we will not stand in his way," he added.
Walsall will retain Hughes's registration which means the player, who made 28 appearances last season, will not be allowed to play for another English-based club for the next 12 months.
Source: BBC Sport
Source: BBC Sport