The Sharks have said only that Couture has an upper-body injury.
Sharks general manager Doug Wilson said no specific return date has been set.
Couture has 14 goals and 21 assists in 43 games this season. After going 11 straight games without a goal, Couture recently scored in four straight. That streak was snapped Sunday in Chicago, but he still had an assist and the shootout winner.
I have been blessed to play for 16 years in the NHL; it has been an amazing ride. I would like to thank the Tampa Bay Lightning and New York Rangers organizations and owners for providing me the opportunity to play the sport I love for so many years. I could have never played for so long or accomplished all that I have without the unwavering love and support from my wife, Heather, our three sons, Ryan, Lucas, and Mason, and my parents.
— Martin St. Louis after announcing his retirement from the NHL on Thursday