Captain Matt Smith to leave A-League champions Brisbane Roar

A-League champions Brisbane Roar have agreed to release their captain Matt Smith, who will join Thai Premier League club, Bangkok Glass later this month, for an undisclosed fee.

Brisbane confirmed that they received a formal offer from Bangkok Glass on Tuesday night.

The 32-year-old Smith, who won three Grand Finals with the Queensland club, had put in a transfer request earlier this month despite having 18 months left on this contract. His last game for Brisbane will be away to Adelaide United on Friday.

Smith's departure is a further setback for the ambitious Australian side who are preparing for their 2015 AFC Champions League campaign. Last month, after a poor start to the season, they sacked their title-winning coach, Mike Mulvey, replacing him with Dutchman Frans Thijssen.

In a statement released by the club, Brisbane Roar football director Ken Stead said they were reluctant to let Smith go, but could understand his reasons for wanting to leave.

"We didn't want to lose our captain and we are sorry to see Matt leave," Stead said.

"But we can understand that as this stage of his career he has made a decision he believes is in the best interest of his playing future and his family.

"It is a significant loss, but it creates an opportunity for another player in the squad while the January transfer window is a timely opportunity for the club to strengthen our squad for the challenges ahead."

Brisbane are seventh on the A-League table after only two wins in their opening nine games.

English-born Smith was on the books of Portsmouth, but never played a first-team match. He joined the Roar in 2010 and was named captain of the club in August 2012. He has made 112 A-League appearances for Brisbane and earned three Australian caps.

It won't be his first time playing in Thailand. In 2007, he represented Great Britain at the World University Games in Bangkok.