Ehn, 22, has split his first season in North America between the NHL and AHL, notching one assist, a plus-two rating, four penalty minutes and eight shots on goal in 10 games with the Red Wings and six points (1-5-6), a plus-five rating, four penalty minutes and five shots on goal in 10 games with the Griffins. Ehn made his NHL debut with Detroit on Oct. 4 vs. Columbus and recorded his first career assist on Oct. 11 vs. Toronto. The Skara, Sweden, native spent the previous three seasons (2015-18) playing professionally for Frolunda in the Swedish Hockey League, producing a career-high 17 points (7-10-17) and 24 penalty minutes in 50 games in 2017-18.

In 147 total SHL games with Frolunda, Ehn registered 32 points (11-21-32) and 38 penalty minutes, adding one goal and two assists in 46 career postseason games. He helped the club win an SHL championship in 2015-16 as well as back-to-back championships in the Champions League tournament in 2015-16 and 2016-17. Originally drafted by the Red Wings in the fourth round (106th overall) of the 2014 NHL Entry Draft, Ehn twice represented Sweden at the IIHF World Junior Championship in 2015 and 2016, totaling four points (1-3-4) in 14 games between the two tournaments. Previous to his draft year, Ehn played in Frolunda's junior ranks, where he was named the league's best forward in 2014-15 after totaling 36 points (12-24-36) in 40 games as Frolunda's captain at the under-20 level.