[5] Prior to joining the Mooseheads, Ehlers spoke with fellow Danishmen Oliver Bjorkstrand and Mikkel Bødker to prepare himself for the change.

[13] Ahead of the 2014 NHL Entry Draft, Ehlers was ranked 13th among North American skaters by the CSS[14] and 10th by Bob McKenzie of The Sports Network.

[16] Leading up to the draft, NHL Director of Central Scouting Dan Marr also praised Ehlers quickness and playmaking abilities.

[18] Following the draft, Ehlers was encouraged by the Jets' coaching staff to add weight and muscle ahead of the 2014–15 season as he weighed only 163 pounds.

[24] In this time span, he also recorded five goals and eight assists over three games and was subsequently honoured with the CHL Player of the Week ending on 30 November.

[28] Ehlers earned his second CHL Player of the Week honour on 10 March after he recorded five goals and seven assists for 12 points over three games against the Acadie-Bathurst Titan, Charlottetown Islanders, and Cape Breton Screaming Eagles.

[35] Following the conclusion of his junior career, Ehlers spent the summer bulking up and joined the Jets' training camp 15 pounds heavier.

He subsequently made his NHL debut on 8 October 2015 as the team's second line winger alongside Mark Scheifele and Mathieu Perreault.

[44] By 4 March, Ehlers had accumulated 13 goals and 31 points through 63 games before suffering an eye injury during an overtime loss against the New York Islanders.

[45] He missed numerous weeks to recover before returning to the Jets' lineup on 24 March to help them beat the Los Angeles Kings 4–1.

[53] He continued to improve throughout January despite losing Laine due to injury and gaining veteran Drew Stafford as the top line's replacement winger.

[57] Following his breakout sophomore season, Ehlers signed a seven-year contract extension with the Jets worth an average annual value of $6.0 million.

[73] Although Ehlers missed Game Five against the Wild due to "general malaise," the Jets clinched their franchises first playoff series win.

[75] Ehlers finished the Predators series with six total assists in the postseason as the Jets met with the Vegas Golden Knights in the Western Conference Finals.

[80] Ehlers' struggles continued into the 2018–19 regular season as he recorded no points and four shots on goal over three games while averaging 12:07 of ice time.

[83] In spite of his early season struggles, Ehlers regained his chemistry with his linemate Laine and the two began producing points at a rapid pace.

[85] On 4 January, during a game against the Pittsburgh Penguins, Ehlers suffered a major lower body injury following a collision with Sidney Crosby.

[97] During practice on 4 November, Ehlers accidentally hit teammate Bryan Little in the face with a puck which resulted in the latter being placed on long-term injured reserve.

[98] As a result, head coach Paul Maurice had to shuffle the forward lines and Ehlers gained Blake Wheeler as his centre along with Jack Roslovic.

[99] While playing on this line, Ehlers tallied his 100th career NHL goal on 19 November to help lift the Jets to their third straight win and a 13–8–1 record.

[103] The line continued to be broken up throughout the second half of the season and Ehlers occasionally played alongside Wheeler, Scheifele, Cody Eakin, and Laine.

[104] While Ehlers and Laine played alongside Cody Eaking over the final eight games of the NHL's regular season, the trio combined for 14 points.

[105] When the NHL paused play due to the COVID-19 pandemic, Ehlers had hit the 20-goal plateau for the fourth straight season and finished with 52 points.

[105] During Game 2 of their Qualifying Round series against the Calgary Flames, Ehlers recorded his first career postseason goal with 9:36 left in the third period.

[113] As the Jets bgean to struggle offensively throughout February, head coach Paul Maurice moved newly acquired Pierre-Luc Dubois between Ehlers and Kyle Connor.

Ehlers scored in the shootout to lift Denmark over Switzerland to lead them to their first win at the top level of the World Junior Championship.

[133] Ehlers returned to Denmark's U20 national team for the final time at the 2015 World Junior Ice Hockey Championships.

During the tournament, he played a significant role in leading Denmark to the Quarter-Finals by scoring in their opener against Team Russia and assisting on two goals against the Czech Republic.

[139] Once the 2022–23 regular season was complete, Ehlers returned to the Danish national team and competed at the 2023 IIHF World Championship.

[143] After his playing career concluded, Heinz became a coach in the Swiss National League A and the entire family moved to Switzerland.