The Detroit Red Wings selected Ehn, a forward from Skara, Sweden, in the fourth round (No. 106) of the 2014 NHL Draft after he made his debut in the Swedish Hockey League as an 18-year-old by playing two games for Frolunda in 2013-14. He continued to play in the SHL through the 2017-18 season before coming to North America for 2018-19.

Ehn is at his best when he's skating and forechecking. He can play on the third and fourth lines, and he's a reliable penalty-killer.

Those skills helped him make the Red Wings out of training camp in the fall of 2018. He made his NHL debut against the Columbus Blue Jackets on Oct. 4, 2018, scored his first point a week later with an assist against the Toronto Maple Leafs and scored his first NHL goal on Dec. 23, 2018, also against Toronto. Ehn finished his first NHL season with nine points (three goals, six assists) in 60 games, averaging 10:37 of ice time.

Ehn played much the same role in 2019-20, scoring four points (two goals, two assists) and averaging 10:25 of ice time in 54 games.