He previously played professionally in Finland with Oulun Kärpät and HIFK of the SM-liiga and with the Minnesota Wild, Nashville Predators, Pittsburgh Penguins, and San Jose Sharks of the NHL.

[5] Granlund sued his old team in July 2009 after Kärpät failed to relent, asking a court to cancel his contracts with them and clear the way for him to play with HIFK.

At the 2010 U18 Championship, Granlund led the tournament in assists with 9, while his 13 total points were third-best as he helped Finland win its second consecutive bronze medal.

[13] Following the 2010–11 SM-liiga season, Granlund made his debut with the senior Finnish national team for the 2011 IIHF World Championship.

Using the "high wrap" in a full-speed variation, Granlund scored a lacrosse-style highlight reel goal in the semifinal game against Russia, helping Finland win gold.

[14][15] In May 2011, HC Dinamo Minsk of the Kontinental Hockey League (KHL) publicly claimed his playing rights because it drafted him one year before his selection by the NHL's Minnesota Wild.

[18] With the NHL lockout postponing the 2012–13 season, Granlund was assigned to the Wild's American Hockey League (AHL) affiliate, the Houston Aeros, to begin the 2012–13 campaign.

Midway through the season, Granlund was moved to Minnesota's top line where he was frequently paired with Jason Pominville and Zach Parise.

The 2015–16 season saw Granlund centre the Wild's second line with a variety of wingers due to Minnesota's struggle with injuries and line-shuffling.

On 6 August 2023, before the start 2023–24 season, Pittsburgh traded Granlund to the San Jose Sharks as part of a three-team deal also involving the Montreal Canadiens.

[30] After Granlund's lacrosse-style goal at the 2011 IIHF World Championship semifinal against Russia, Finnish Hockey Mafia released the single "Taivas varjele!"