The 35-year-old center was injured after colliding with Buffalo Sabres forward Tage Thompson in the first period of the Wild's 5-4 shootout loss at KeyBank Center on Tuesday. He is expected to have surgery Friday.
Koivu, the Wild captain, had 29 points (eight goals, 21 assists) in 48 games this season.
The No. 6 pick by Minnesota in the 2001 NHL Draft, Koivu has 688 points (201 goals, 487 assists) in 973 games and 14 NHL seasons, all with the Wild.
Koivu is Minnesota's all-time leader in games played, points, assists, shots (2,196), power-play points (244), game-winning goals (33) and shorthanded goals (10).