[1] His father Jeff played college hockey at Lake Superior State and was a Colorado Rockies draft pick.

[2] His uncle Steve Jensen also played hockey for the Minnesota North Stars and Los Angeles Kings and was an Olympian with Team USA at the 1976 Winter Olympics.

[3] He graduated to the Green Bay Gamblers of the United States Hockey League (USHL) and in his first season in 2008–09, he registered five goals, 17 assists and 22 points in 52 games.

[4] The Gamblers made the playoffs again that season and he was instrumental in the team's run to the finals where they won Clark Cup as league champions.

Cloud State Huskies in the NCAA Men's Division I Western Collegiate Hockey Association (WCHA) conference.

After sweeping Nebraska Omaha in the first round of the playoffs, the Huskies suffered a season-ending loss to North Dakota in the quarterfinal.

Cloud State, and was named the WCHA's Defensive Player of the Year and selected to the NCAA West First All-American Team.

Cloud State defeated Notre Dame, 5–1, and Miami, 4–1, to capture the NCAA Midwest Regional before falling to Quinnipiac, 4–1, in the Frozen Four semifinals.

[10] He was assigned to Detroit's American Hockey League (AHL) affiliate, the Grand Rapids Griffins for the 2013–14 season.

[4][11] The 2015 Calder Cup playoffs saw the Griffins go on a deep run making it to the Western Conference Finals, before ultimately losing to the Utica Comets.

[20] He registered his first three point game on October 18 versus the Toronto Maple Leafs, assisting on goals by Dylan Larkin, Tomáš Tatar, and Jonathan Ericsson in a 6–3 loss.

[22] He marked his first multi-goal game on October 11, scoring two goals against Frederik Andersen in a 5–3 loss to the Toronto Maple Leafs.

[22] He had fallen down the depth chart behind the younger Gustav Lindström and the Red Wings had not agreed with his demands in contract negotiations.

[26] He marked his first point with the Capitals on March 6 assisting on Nicklas Bäckström's second period goal in a 5–3 win over the Philadelphia Flyers.

[4] Prior to the 2021 NHL expansion draft, Jensen was among those players left unprotected by the Capitals for the Seattle Kraken to chose from.

[4] In the 2022 Stanley Cup playoffs, the Capitals were eliminated by the Florida Panthers in the first round, with Jensen appearing in all six games, going scoreless.

[4] On April 13, 2024 he took a hit from Mikey Eyssimont of the Tampa Bay Lightning along the boards that left him needing a stretcher in order for him to leave the ice.

[39][40] On July 1, 2024, the Capitals traded Jensen, along with a third-round pick in the 2026 NHL entry draft, to the Ottawa Senators in exchange for Jakob Chychrun.

[41] On April 28, 2018, Jensen and Red Wings teammate Dylan Larkin were named to the United States men's national ice hockey team to compete at the 2018 IIHF World Championship.