Boston Bruins
When touching on teams that need help down the middle, Boston will always be near the top of the list. They're still searching for the heir to Patrice Bergeron after his retirement, and while Mikael Granlund is not going to be the perennial favorite for the Selke like Bergeron was, he's a fantastic center capable of helping fill the void left by the retired Quebecois centerman.
Boston has some cap issues. With less than $800,000 in space, the Sharks would need to take on some money to balance the books. Whether that's acquiring Morgan Geekie or Trent Frederic as part of the return, or if it's the Bruins adding to someone like Pavel Zacha, the deal would have to be complicated. There's not a world where the Bruins simply acquire the Finn.
Regarding what the Bruins can offer, I'd assume that Grier would be demanding someone like Matthew Poitras to be included in the deal for Granlund. I also think Don Sweeney would go blue in the face screaming at the notion, so I'm not quite sure what the Bruins would part with for Mikael Granlund. He's going to be a drastic improvement on what they already have, but there aren't the assets there to naturally land it.