Selected by the Washington Capitals with the No. 18 pick in the 2003 NHL Draft, Fehr was a junior scoring star with Brandon in the Western Hockey League, posting back-to-back 50-goal seasons in 2004 and 2005. Fehr's 111 points in 2005 led the league and he was named the Four Broncos Memorial Trophy winner as the player of the year.

The honors continued his first year as a pro in 2005-06 when he scored 25 goals to lead Hershey of the American Hockey League to the Calder Cup.

Unfortunately, that's when injuries hit. Before Fehr could land a regular spot in the Washington lineup he was diagnosed with a herniated disc in his back in late February 2007. He did not return until Feb. 5, 2008. Surgery on both shoulders curtailed Fehr's scoring in 2008-09 and 2010-11, although he had 21 goals and 39 points in 69 games in 2009-10.

Fehr was traded to the Winnipeg Jets before the 2011-12 season, but after one season returned to the Capitals as a free agent and rejuvenated his career in a different role. Instead of serving as a potential top-six scoring threat, Fehr was used in more of a lower-line role where he thrived, getting 41 goals in three seasons.

Though Fehr underwent elbow surgery following the 2014-15 season, he signed a three-year contract with Pittsburgh and turned into a shutdown center for the 2016 Stanley Cup champions.

Fehr is also an author. He co-wrote "The Bulliest Dozer," an anti-bullying story for children published in 2014, with proceeds going to charity.