Steen, 32, had shoulder surgery in June and will not be able to compete in the tournament.
"Of course it is a blow to our team that Alex can't participate in the World Cup of Hockey because he possesses a unique set of skills on our team," Sweden coach Rikard Gronborg said. "However, Rickard Rakell will be a very strong offensive power on our team. What he accomplished last season in Anaheim is just a sample of what kind of player Rickard will be in the near future."
Rakell, 23, had 20 goals and 23 assists for 43 points in 72 games for the Ducks in 2015-16. Steen had 17 goals and 35 assists for 52 points in 67 regular-season games for the Blues. The veteran forward added 4 goals and 6 assists for 10 points in 20 playoffs games last season.