"Naturally, we're bitterly disappointed but we're satisfied we did everything we could to persuade Robbie to come to Sydney FC, Australia and the Hyundai A-League competition," said the Aussie club's chief executive George Perry.
"Robbie was tremendously impressed by what he saw in Sydney but he's chosen to go elsewhere. We respect his decision and wish him and his family well."
Cardiff City are now the favourites to sign Fowler although Leicester are also in the hunt.