Armalis began his career with the Djurgårdens IF's under-16 squad during the 2007–08 season, but moved to the Mora IK organization where he played for their junior J18 and J20 teams from 2007 to 2011.

[3] Prior to signing with the Sharks, the Toronto Maple Leafs were considered favourites to land Armalis.

[5] On 3 October 2016, Armalis was assigned to the Sharks' American Hockey League (AHL) affiliate San Jose Barracuda.

[6] After the 2016–17 season, the Sharks decided not to issue a qualifying offer to Armalis and he would become an unrestricted free agent on 1 July 2017.

[12] He was named Best Goalkeeper of the tournament at 2012 IIHF Ice Hockey U20 World Championship Division II Group A in Ukraine.