Thwaite took over as captain at the start of last season, after the retirement of previous skipper Jacob Burns at the end of the 2013-2014 campaign.
Despite the one-time Socceroos defender playing in and Inglewood United it was another ex-Socceroos player in Garcia that wore the captain's armband.
Sources in the west have told The World Game Thwaite is already aware he won't be captain for the upcoming season.
The tip is that either Garcia or Dino Djulbic will be captain.
Thwaite's central-defensive partner , and .
But there has been no statement from the club regarding the leadership role.
Perth is next scheduled to play in an all-A-League FFA Cup Round of 32 game against Newcastle Jets at Magic Park, Broadmeadow, on Tuesday 11 August.
That will be the club's first outing in an official competition since the end of last season and should provide a clearer guide as to will be the captain heading into the A-League.
Many of the Glory players were left disillusioned when the club was caught rorting the salary cap last season and subsequently penalised by FFA. Perth was banned from competing in the finals series and heavily fined.
Some senior players were particularly upset the club had put the team's campaign at risk in such a way and made their thoughts known internally.
Several senior players contracted into the coming season at the club, including goalkeeper Danny Vukovic and defender Scott Jamieson, have since left Glory for other A-League outfits after their requests for releases were granted.
It is understood Thwaite was told he was free to leave the club at the end of last season, but despite there being serious interest in the 32-year-old from a couple of other A-League clubs he chose to continue on his existing deal at Perth.
