Career
He is currently playing with Modo Hockey of the Swedish Hockey League (SHL). In 2008, this JYP-trained player began playing in the Master of Science-liiga for the Espoo Blues. In the 2009 National Hockey League Entry Draft, he was chosen in the third round, 65th overall, by the Montreal Canadiens.
On May 26, 2011, Joonas signed a three-year, entry level contract with the Canadiens worth $1.825 million at the National Hockey League level
Whilst in the final year of his contract during the 2013-2014 season, Nättinen was recalled from affiliate, the Hamilton Bulldogs of the American Hockey League, and joined the Canadiens on January 17, 2014. He made his National Hockey League debut the following day in a brief appearance for the Canadiens in a defeat against the Toronto Maple Leafs.
After his singular game with the Canadiens, Nättinen was returned to the Bulldogs for the remainder of the season. On June 5, 2014, as a restricted free agent, Nättinen opted to return to Europe signing a one-year contract with Modo Hockey of the Swedish Hockey League.