Miller shocked many at the end of last season when he turned down a contract extension with the Glory before signing with the Roar soon after.
It was thought the sacking of Ferguson, who was instrumental in luring Miller to the A-League, midway through last season was the reason behind the Irishman's decision to leave the club.
But Miller has set the record straight, insisting the challenge of starting over at a new club and moving his family to the East coast were key factors in his decision.
"I'm very grateful to Ferguson and obviously he brought us over (to Australia) and I had a great year and a half under him," Miller told <i>Sportal</i>.
"You don't like to see any manager get the chop and I wish him well. I enjoyed my time there, we got to the grand final but it just wasn't meant to be.
"It shows how football can be great one minute as a manager and then the next you're out of a job.
"But him moving on it didn't have too much of an effect on me to be honest.
"I was looking for a move to the East coast and Brisbane was definitely a club that appealed to me and my family so that was the main reason for moving there."
And while he's only a few weeks into pre-season training under Mike Mulvey at the Roar, Miller is excited about the club's prospects for the new season.
The classy midfielder will link up with German ace Thomas Broich and star striker Besart Berisha in what looms as an imposing attacking triumvirate for the two-time champions.
"You see Thomas (Broich) playing in the league and you play against him and Bes (Berisha) and Michael (Theo) and you don't realise how good players they are until you play alongside them," Miller said.
"I've got to know the lads over the last two months in training and they are a good bunch.
"We've been working hard in the pre-season...it's only been five weeks since we've been back but I've been enjoying it.
"I'm really looking forward to the start of the league; it's exciting so hopefully there's good things ahead for Brisbane."