The 32-year-old, who skippered the Roar to the A-League title last season, is under contract until 2016 but, according to reports in the Australian media, was expected to be released early to facilitate the move.
Brisbane, without denying an approach had been made, took the unusual step of commenting public on the speculation hours before their match away to Melbourne City on Sunday.
"Matt has been an important part of our club's success over the last four years. We helped revive his career in 2010 and he still has another year on his contract with the Roar after this season," Fong said in a statement.
Former Western Sydney Wanderers defender Jerome Polenz, as well as Luke DeVere and Robert Cornthwaite, are reportedly being targeted by the Roar as potential replacements for Smith, with director of football Ken Stead also quoted in the club's statement.
"We will be strengthening our squad for next year's AFC Champions League campaign," he said.
The Roar have endured a tumultuous title defence so far in 2014-15, allowing Liam Miller to walk away from the club before sacking coach Mike Mulvey, who has been replaced by Dutchman Frans Thijssen on an interim basis.
They will be without star playmaker Thomas Broich for the remainder of 2014 after the German underwent ankle surgery.