2005-06: Carlson scored 2 goals with 10 assists and 42 PIM in 38 games for the New Jersey Rockets in the Atlantic Junior Hockey League. He was selected by the Indiana Ice in the third round (32nd overall) of the 2006 USHL Entry Draft.
2006-07: Carlson played for the New Jersey Rockets in the Atlantic Junior Hockey League before making his USHL debut in two games with the Indana Ice. He scored 12 goals with 38 assists and 98 PIM in 44 games for the Rockets. Carlson played for the South team in the AJHL All-Star Game.
2007-08: Carlson played 59 games for the Indiana Ice in the USHL. He scored 12 goals with 31 assists and was +11 with 72 PIM. Seven of his 12 goals were scored on the power play. Carlson played for the Eastern Division in the USHL Prospects/All-Star Game. Carlson was selected by the London Knights in the second round (33rd overall) of the 2008 OHL Priority draft and decided to play major junior hockey after previously having committed to attending the University of Massachusetts-Amherst in 2009-10. Carlson attended the USA WJC Evaluation Camp.
2008-09: Carlson finished second on the team in points and plus/minus in his first season with the London Knights. He scored 16 goals with 60 assists and was +23 with 65 PIM on a London team that finished first in the OHL’s West division. Carlson scored 7 goals with 15 assists in 14 playoff games finishing +11 with 16 PIM. London defeated Erie and Saginaw in the first two rounds before falling to eventual Memorial Cup champion Windsor in a five-game series in which all five games were decided in overtime. Carlson joined Washington’s affiliate Hershey during the AHL playoffs and stepped into a regular role as the Bears captured a Calder Cup trophy. In 16 playoff games he was +3 with 2 goals and 1 assist.
2009-10: Carlson had quite a first season as a 19-year-old rookie in pro hockey while also scoring one of the biggest goals in Team USA junior hockey history. Carlson made his NHL debut on Nov 20 with Washington after opening the season with Hershey in the AHL. After appearing in three games he returned to Hershey before joining Team USA at the U-20 WJC. He returned to the Capitals three other times and played in all seven playoff games. Carlson scored his first NHL goal on March 25 against Carolina in a 3-2 shootout loss to the Hurricanes and finished the season with 1 goal 5 assists and was +11 with 8 PIM in 22 games. In the Capitals’ first-round, upset playoff loss to Montreal, he had 1 goal with 3 assists and was +6. With Hershey, Carlson finished second to Steve Pinizotto with a +37 plus/minus and scored 4 goals with 35 assists and 26 PIM in 48 games. He re-joined the Bears following the NHL playoffs and scored 2 goals with 5 assists and was +7 with 8 PIM in 13 games as Hershey captured its second straight Calder Cup title. Carlson’s most exciting moment may have come in the WJC U-20 championship game as his overtime goal in the tournament final ended Canada’s string of four straight championships and gave Team USA the gold medal. An assistant captain for Team USA, Carlson scored 4 goals with 3 assists and was +8 with 2 PIM in seven games.
Carlson is blessed with size, strength and skating ability and is a very talented blueliner with an NHL skill set. He is a great playmaking defenseman, who’s very responsible in his own end. He plays a very controlled, smart and methodical game. Carlson sticks to the system and playing within reason. He works the opposition hard, plays in tight situations and is one of the team’s top penalty-killers. Carlson has great instincts and times the game effectively. He is very coachable and willing to do what it takes to win. Carlson has developed an offensive component to his game to compliment his strong defensive play.