Sedin suited up Wednesday night in Game 4 against the eighth-seeded Los Angeles Kings, who have a 3-0 lead in the series.
Vancouver's leading goal-scorer hadn't played since a dangerous hit from Chicago's Duncan Keith left him with a concussion on March 21. Sedin flew to Los Angeles to join his teammates for practice on Tuesday.
Sedin was a Hart Trophy finalist last season. He had 30 goals and 37 assists this season.
Vancouver finished the regular season strong with eight wins in nine games after Sedin's injury, but managed just four goals in the first three games against the Kings, with the power play going 0 for 14.