The Nashville Predators and St. Louis Blues have taken advantage of this rule by completing a transaction involving Anthony Angello.
The 27-year-old center has only played 31 NHL games in his career, all with the Pittsburgh Penguins. However, this season he has played 45 games with the Springfield Thunderbirds, where he scored six goals, made five assists, and accumulated 65 penalty minutes.
In exchange for Angello, the Blues will receive future considerations from the Predators.