The Swedish rearguard is in the midst of his 11th NHL season—his second with the Sharks—and he was enjoying another productive campaign to the tune of a team-high 40 points (six goals and 34 assists) across 56 appearances.
San Jose acquired Karlsson from the Ottawa Senators in an offseason trade prior to the 2018-19 campaign that sent forwards Josh Norris, Chris Tierney and Rudolfs Balcers, defenseman Dylan DeMelo and three draft picks to Ottawa.
The Karlsson trade came after his numbers dipped a bit in his final season with the Sens. He finished with nine goals and 53 assists for 62 points in 2017-18, marking his lowest goal and point totals since 2012-13 when he appeared in just 17 games.
Karlsson was also a minus-25, which was the second-worst rating of his career.
Although injuries limited him to 53 regular-season games in 2018-19, he was productive when healthy with 45 points during the regular season and 16 points in 19 playoff games.
The All-Star blueliner is just three seasons removed from a campaign that saw him register 17 goals and 54 assists for 71 points, along with a plus-10 rating. He also added 18 points in 19 playoff games, with Ottawa falling just one win short of the Stanley Cup Final in 2016-17.
The previous season was arguably the best of his career; he posted personal bests with 66 assists and 82 points.
He is a two-time Norris Trophy winner as the NHL's best defenseman, and the 29-year-old is undoubtedly among the top players at his position. However, his injury could spell doom for a club that has disappointed thus far with a 25-28-4 record that sees them 20 points back from a wild-card spot.
San Jose will now lean more heavily on Brent Burns to pick up the slack offensively on the back end. Marc-Edouard Vlasic and Brenden Dillon will also be tasked with taking on a greater role during the Swede's absence.