Hartman will join Team USA at the IIHF World Championship.
Hartman will be joined in Finland by teammates Matthew Boldy and Jon Merrill after the Wild were bounced in six games by St. Louis in Round 1. Team USA is 1-0 after beating Latvia on Friday and has six more games scheduled during round-robin play, allowing Hartman to represent his country for the first time since 2013-14 at the World Juniors.