Hughes, 48, who replaced Neale Cooper at Victoria Park earlier this month, lost his first two games in charge of League One's bottom club, but stopped a run of five straight defeats with a draw at Walsall last weekend.
"There have been no promises from day one," Green said. "We've always been realistic. He's not said 'I will keep you up'. Nobody can say that in football, if they could they would be magicians and manager at Man United.
"But there's always a gamble, don't get me wrong, bringing him to his first job in England. But we feel that the odds are stacked in our favour with choosing John and taking the gamble we've made."
Hughes' side, recently thrashed 6-1 at Chesterfield in the FA Cup, are without a fixture this weekend as the competition stages the second round proper.