Gardner was injured during Chicago's loss to the Washington Mystics on Friday and had to be helped off the floor into the locker room. Coach James Wade said the surgery was to address a break in Gardner's foot.
Gardner -- who went undrafted out of UCLA in 2012 -- made a splash last year in her first WNBA season, averaging 8.4 points, 3.3 rebounds and 1.4 steals in 21.7 minutes per game for the championship-minded Sky and earning a spot on the 2022 WNBA All-Rookie Team. Chicago, the 2021 WNBA champion, was later upset in the semifinals by the Connecticut Sun.
Gardner's absence marks yet another injury for the new-look Sky, who lost four starters during the offseason and return just four players from last year's roster.
Isabelle Harrison is also out for the time being after undergoing knee surgery, and Ruthy Hebard has yet to return from maternity leave. Rookie Morgan Bertsch injured her ankle in the same game Gardner got hurt in and hasn't appeared since.
Despite the roster fluctuation and injuries, the Sky are 3-2, narrowly losing to the Mystics before dropping their last contest to the Atlanta Dream by 18. They next face the New York Liberty on Friday at home.