Schmaltz, 23, dressed in nine regular season games with the Blues in 2016-17, posting two assists and four penalty minutes. The 6-foot-2, 200-pound defenseman also made his NHL postseason debut in Game 1 of the first-round series between the Blues and the Minnesota Wild on April 12.
The Verona, Wisconsin native also appeared in 42 regular season games with the Wolves this season, totaling 25 points (three goals, 22 assists) and 22 penalty minutes.
Schmaltz was drafted by the Blues in the first round (25th overall) of the 2012 NHL Entry Draft.