Dahlstrom was a fairly high draft pick, going in the second round (51st overall) to the Chicago Blackhawks in 2013. He came to the US in 2015, and spent three seasons in the AHL before getting to the NHL. After another two seasons in Chicago, where he did play in the big league, Dahlstrom headed to Winnipeg after being placed on waivers by the Blackhawks. He played 15 games for the Jets before being traded to Vegas, along with a fourth round pick, for Paul Stastny. He left Vegas as a free agent, signing in Toronto. He played just three games for the Maple Leafs over two season, spending the rest of his time with the AHL's Toronto Marlies. During the 2022-23 preseason, it was announced Dahlstrom needed shoulder surgery and would be out six months after taking a hit from Rem Pitlick of the Montreal Canadiens.