|Born||June 6, 1987|
|6 ft 3 in (1.91 m)|
205 lb (93 kg; 14 st 9 lb)
|NHL Draft||108th overall, 2005|
Niklas was drafted 108th overall in the 2005 NHL Entry Draft by the Blackhawks. He played professionally for 3 years in the Elitserien with HV71. In the 2007–08 season, his first in North America, he made his NHL debut with the Blackhawks.
After spending the majority of the season with the Rockford IceHogs, he procured a regular spot on the roster with James Wisniewski's trade to the Anaheim Ducks and scored his first NHL goal against Chris Osgood of the Detroit Red Wings.
Niklas became a major installment into the Blackhawks lineup late in the 2008–2009 season and coming into the 2009–2010 season.
He played 77 games in the regular season and all 22 in the playoffs for the team, tallying over 19 minutes per game, switching between a position in the second and third lines of defensive pairings. Over that time, Niklas recorded a production value (PROD) of a point roughly every 45 minutes of it while his season PROD was 89 minutes.
A slapshot of Niklas' was redirected by Andrew Ladd to take a 3–2 lead in game 6 of the Stanley Cup Finals where his team won in 4–3 in overtime. He won the Stanley Cup with the Chicago Blackhawks in 2010.
On July 9, 2010, Niklas signed an offer sheet with the San Jose Sharks for 4 years and $14 million. On July 12, 2010, the Chicago Blackhawks announced that they would match the offer sheet. He was the first defenseman in 13 years to receive an offer sheet as a restricted free agent.
Critically, Chicago's matching of the offer sheet meant that they did not have enough cap space to re-sign Antti Niemi, who ended up joining the Sharks later that offseason.
During the 2012–13 NHL lockout, Niklas played in italian Serie A and in the IIHF Continental Cup with the HC Bolzano. In 2013, the Chicago Blackhawks won the Stanley Cup. He became the 10th Swede to win the Stanley Cup more than once.
During the 2013 off-season, he signed a five-year extension with the Blackhawks, at an annual average salary of $4.1 million.
The Blackhawks won the Stanley Cup again in 2015, making him one of only seven players to be part of the 2010, 2013 and 2015 Stanley Cup victories.
After the 2016–17 season (in his tenth year with the Blackhawks), Niklas' tenure with the club came to an end as he was dealt to the Arizona Coyotes in exchange for Connor Murphy and Laurent Dauphin on June 23, 2017.
Regular season and playoffs
|Men's ice hockey|
|Competitor for Template:SWE|
|IIHF World U18 Championships|
Niklas participated in the 2005 IIHF World U18 Championships where he won a bronze medal. In 2014, he was chosen to play on Team Sweden in the 2014 Winter Olympics in Sochi, Russia where Sweden won a silver medal.
- 2005 U18 WJC Bronze Medal
- Stanley Cup Champion (2010, 2013 & 2015)
- Olympic Silver Medal (2014)
In 2013, Niklas married Elina Casell and they have two sons: Theo (born in April 2014) and Oliver (born in April 2017).