[1] RoKi struggled for wins in the regular season but Pirttijärvi continued to standout as the team’s leading scorer, amassing 28 points in thirty games.
Three games in to the 2021–22 Naisten Liiga season, Pirttijärvi and RoKi teammate Aino Karppinen were requested by Luleå HF/MSSK of the Swedish Women's Hockey League (SDHL) as loans to fill-in for roster holes left by injuries and suspensions.
When her contract was announced, GM Mikael Forsberg highlighted her physical strength, high compete level, and continuous commitment to improving as a hockey player as key assets she brought to the team.
Pirttijärvi made her debut on Luleå HF/MSSK's top line on 19 February, playing alongside Finnish Olympic medalists Noora Tulus and Viivi Vainikka in the thirtieth game of the 32-game regular season.
As a result, she reduced her full-time work as a youth counselor by about twenty percent, to allow for more time to travel between her home in Rauna and the rink in Rovaniemi.
[11] She also attended training camps in the summer of 2023, appeared in a friendly against Japan in August 2022, and participated in the first two tournaments of 2022–23 Women's Euro Hockey Tour (EHT).