The 30-year-old Perquis spent the last three seasons with Spain's Real Betis after stints with several French clubs.
The six-foot-one Perquis has earned 13 caps for the Polish national team. While born in France, he is of Polish descent through his grandmother.
Toronto acquired Zavaleta, the nephew of Toronto head coach Greg Vanney, in a trade that sent a second round pick in the 2016 MLS SuperDraft to Seattle.
The 22-year-old Zavaleta spent the 2014 season on loan at Chivas USA, where he made 17 appearances and started in 15 matches
The defenders fill a void on the Toronto roster. The MLS club was lacking depth in its backline.