Gallas limped off before halftime, with the 36 year-old to undergo scans on Monday to determine the extent of the damage.
The former French international has been plagued by calf troubles since signing with Glory in October, and his latest setback means he is unlikely to front up for the final two games of the season.
Gallas's contract, believed to be worth in the vicinity of $800,000, runs out at the end of the season, and it remains unclear whether he wants to continue his career in Perth.
Even if he is keen to stay, Glory will wait until it finalises its next coach before making a decision.
Interim coach Kenny Lowe, who is in the running for the full-time position, said Gallas had made a significant contribution at the club both on and off the field.
Lowe felt Gallas has been unfairly criticised this season by people who may not fully understand the game.
"Maybe the uninitiated and not football-savvy people think he's going to pull it down, go past 12, do an overhead kick and stick it in the seven every game," Lowe said.
"But that's not how it works.
"He's an out-and-out defender. If you watch him, he smells danger. He's a top guy. He mentors people at the club."
Glory's win over the Jets boosted its chances of avoiding the club's first ever wooden spoon.
Perth remains last on the table, behind Melbourne Heart on goal difference.
Glory hosts Central Coast on Saturday night before rounding out its season against Sydney FC at Allianz Stadium.
Heart tackles Adelaide United away on Friday night before hosting Western Sydney Wanderers.