Rosen, 27, came over from Sweden in 2017 as a highly-touted defenseman, but has struggled to find his way in the NHL. With just 20 games at that level to this point, a deal here for the Blues is more about minor league depth than anything else. In 2020-21, Rosen spent the entire season with the Toronto Marlies, scoring 13 points in 20 games.
He’s proven himself to be an excellent AHL option, even able to play the top-pair at times. While there may be a handful of NHL games in his future should the Blues experience several injuries, the depth chart is looking pretty long already. St. Louis has seven defensemen under one-way contracts, plus names like Steven Santini and Scott Perunovich waiting for an opportunity. Rosen is likely ticketed for the Springfield Thunderbirds after training camp, as long as he clears waivers.