Rosen was sent to AHL Springfield on Thursday, Lou Korac of NHL.com reports.
Rosen was called up from AHL Springfield on Thursday, per Jeremy Rutherford of The Athletic.
Rosen was waived by the Blues on Sunday, Chris Johnston of TSN reports.
Rosen scored his eighth goal of the season in Saturday's 6-1 loss to the Predators.
Rosen notched a goal and a plus-1 rating during a 5-2 loss to the visiting Wild on Saturday.
Rosen scored a goal on two shots in the Blues' 5-4 loss in overtime to the Maple Leafs on Tuesday.
Rosen scored a lucky-bounce goal during Wednesday's 5-2 victory over the host Blackhawks.
Rosen scored a goal and registered an assist in Thursday's 5-3 win against the Sharks.
Rosen signed a two-year, two-way contract extension with the Blues on Wednesday.
Rosen was waived by St. Louis on Saturday, James Mirtle of The Athletic reports.