Coach Mike Yeo said Stastny is day-to-day. St. Louis is up 3-0 in its first-round series against the Minnesota Wild, with Game 4 at home Wednesday night.
Stastny, who has 18 goals and 22 assists in 66 games this season, was injured against Colorado on March 21 after being hit in the foot on a shot by Vladimir Tarasenko.
Stastny also worked with the No. 1 power play unit.