He began his professional career with Sweden's Brynas IF in 2002.
Selected 4th overall by the Capitals in 2006, he was named to the NHL's All-Rookie Team after the 2007-08 season and was a finalist for the league's Rookie of the Year award.
His father Anders played hockey professionally in Sweden and his mother Catrin played handball professionally in Sweden and in her native country Finland.
Playing alongside superstar Alexander Ovechkin, he became one of Washington's top point scorers on a yearly basis. In the 2009-10 season he dished out 68 assists and tallied 101 points.