Defender Scott Galloway has also moved on, although the club says this is unrelated to his trial with Dutch top-flight club Willem II.
Faty and Tavares were signed by former Mariners coach Tony Walmsley after being let go at the end of last season by Sydney FC.
At the time, it appeared a win for the club, who were in dire need of experience to balance out their youth after a desperately poor wooden-spoon campaign.
However, the duo went on to play just eight games each under current manager Paul Okon, as both juggled extended injury layoffs, defender Faty with a troublesome hamstring and midfielder Tavares an ankle issue.
It's believed Faty's season-ending problem, for which he sought unsuccessful treatment in Europe, developed into a potentially ugly insurance issue over his pay.
But with both players' contracts finished, the club will have two extra visa spots to play with in 2017-18.
Okon has just returned from a scouting mission to Spain, Belgium, Holland and the UK, using his European playing connections to watch a range of games and sample talent to try to shape his own squad after an encouraging season.
Galloway left this week for Europe to trial with Willem II. It's understood he is keen to explore other opportunities regardless of his fortunes in Holland.
The 22-year-old has flourished since joining the Mariners early last season from Melbourne Victory, starting in all but one game.
Head of strength and conditioning Brice Johnson and head of medical Andrew Nealon will also depart to pursue other opportunities.