MacEachern, 24, was originally drafted by the Blues in the third round, 67th overall, of the 2012 NHL Draft.
Currently in his rookie season, the 6-foot-3, 197-pound forward has recorded three points (two goals, one assist) and two penalty minutes in 10 games with the Blues. The Bloomfield Hills, Michigan native has also appeared in 33 games with the Blues' AHL affiliate, the San Antonio Rampage, this season, tallying 16 points (nine goals, seven assists) and 18 penalty minutes.