Last season the Sharks finished 29th in the National Hockey League, only 2 points ahead of the last place Anaheim Ducks. Without Karlsson the Sharks would have easily finished dead last in the league. So, after some difficult conversations both the Sharks and Karlsson have decided that it would be best for both parties to part ways.
Karlsson is still seeking his first Stanley Cup, one of the only things left for him to accomplish. Unfortunately, given the direction of the Sharks, Karlsson won't have an opportunity to win a Cup there. The Sharks have been actively trying to trade Karlsson, with the Carolina Hurricanes and Pittsburgh Penguins as the rumored favorites, but according to Hockey Insider Eklund, the Sharks would actually prefer to send Karlsson to the Toronto Maple Leafs.