Unable to make a senior appearance with Frölunda, on 3 July 2014, Rosén signed with his hometown club, Växjö Lakers of the Swedish Hockey League (SHL).

[1] In late April 2017, rumours began to circulate that Rosén was being pursued by various National Hockey League teams as a free agent, headlined by two strong pushes from the Toronto Maple Leafs and Chicago Blackhawks.

[8] During the 2018–19 season, while playing on assignment with the Toronto Marlies, Rosén signed a two-year, one-way, $1.5 million contract extension with the Maple Leafs on 10 December 2018.

With an expanded role with the Colorado Eagles, Rosén was unable to match his previous seasons offensive totals, recording 3 goals and 15 points through 35 games.

Following three seasons within the Blues organization, Rosén left as a free agent and was signed to a one-year, two-way contract in a return to formerd Colorado Avalanche, on 1 July 2024.