Tarasenko will be placed on long-term injury reserve and will be reevaluated in five months, meaning he will miss the majority of the 2019-20 season.
Tarasenko suffered the injury in a game against the Los Angeles Kings on Thursday in the first period. At the time, he had points in five straight games. He has three goals in seven assists in 10 games this season.
Tarasenko, 27, who did not travel with the Blues for their two games this past weekend, had reconstructive surgery in April 2018 to repair a dislocated left shoulder. Following the Stanley Cup in June, the team announced that he also had a successful arthroscopic surgery on his left knee.
He scored 68 points (33 goals, 35 assists) in 76 regular-season games last season, and he had another 11 goals and 17 points in 26 playoff games en route to the Blues winning the Stanley Cup.
St. Louis is 6-3-3 this season and is in third place in the Central Division entering Monday’s games.