SAN JOSE - At the start of the 2018-19 regular season, all eyes were on the Sharks' defense after the team acquired Erik Karlsson and gave themselves one of the most dangerous-looking blue lines in the league.

With San Jose's offseason underway, the focus yet again is on the Sharks' d-corps and the decisions that could change how it looks next season -- and those changes aren't just hinging on whether Karlsson stays in San Jose for another season.

For starters, Karlsson isn't the only Sharks' d-man hitting free agency. Joakim Ryan and Tim Heed, who penciled into the lineup at various times this season when Karlsson was injured, are both without new contracts ahead of July 1. Neither one is guaranteed to come back, although Heed's chances of staying in teal seem a bit higher.

Even though Ryan, who will be a restricted free agent this summer, saw more playing time during the playoffs than pending unrestricted free agent Heed did, it never seemed like Sharks coach Peter DeBoer was completely satisfied with what he saw from No. 47. While the Sharks benefitted from having both players down the stretch when the blue line got banged up, it seems likely San Jose will give Barracuda blueliner Jacob Middleton a longer look at the NHL level in place of Ryan. 

Keep in mind, the Sharks also are hoping to have Radim Simek back healthy at the start of the next season. The Czech d-man has already made huge strides in recovering from a devastating knee injury that cut his impressive rookie campaign short.

 

According to teammate and fellow countryman Tomas Hertl, Simek has been "working really hard" and "will for sure be ready for next year." It's fair to say San Jose's defense looked its best when both Simek and Karlsson were in the lineup healthy. With Simek back alongside Norris Trophy hopeful Brent Burns next season, the Sharks' d-corps will get an instant boost.

Speaking of Burns, San Jose's blue line is already primed to look a little different next season now that Bob Boughner is rejoining the coaching staff. Boughner did great work with San Jose's blue line before taking the head coaching job with the Florida Panthers, including working No. 88 during this Norris-winning campaign. Just imagine the impact he could have on a defense with both Burns and Karlsson in the mix -- if Karlsson does, in fact, stay in the South Bay.

This brings us back to Karlsson, who is still the big player to watch. When addressing the media on locker cleanout day, Karlsson didn't give any indication as to whether he wanted to stay in San Jose or go somewhere else. Despite posting a tweet to Sharks' fans that looked as though he may have been saying farewell, SportsNet's Elliotte Friedman reported just a week later that Karlsson is strongly considering whether he wants to remain in San Jose.

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Although his 2018-19 campaign was hampered with injuries, Karlsson clearly was a good fit on the Sharks' blue line when he was healthy, tallying 45 points (three goals, 42 assists) through the regular season and 16 points (two goals, 14 assists) through the playoffs. 

Suffice to say even after Karlsson makes a decision, San Jose's blue line will remain an entity to watch as we get closer to the opening of free agency.