Eminger, who is also known for his physical play, started his hockey career with the
Kitchener Rangers of the
Ontario Hockey League in 1999. He was drafted in the first round, 12th overall by the
Washington Capitals at the
2002 NHL entry draft. He made his NHL debut the next season, but after 17 games in Washington he was sent back down to Kitchener. Kitchener was strengthened by Eminger's return, and they won the
Memorial Cup. Since leaving junior hockey, Eminger split his time between the Capitals and their AHL affiliate, the
Portland Pirates. Despite the lofty projections that came with his first-round-pick status, Eminger has failed to live up to expectations. Throughout the
2007–08 NHL season, the final season of his contract, Eminger spent a great deal of time as a healthy scratch. However, during the 2008 playoffs the Capitals were decimated by injuries and Eminger was put into the lineup with a larger role. During these playoffs, Eminger suddenly found his niche and proved himself to be a solid defenceman. During the
2008 NHL entry draft, Eminger, along with the 84th overall pick (
Jacob De Serres) were traded to the
Philadelphia Flyers for the 27th pick overall (
John Carlson). On June 29, 2008, Eminger and the Flyers agreed to a one-year contract. After 12 games with the Flyers, Eminger was traded to Tampa Bay on November 7, 2008, along with
Steve Downie and a 4th-round draft pick for
Matt Carle and a 3rd-round draft pick. On March 9, 2009, on the day of the trade deadline, Tampa Bay traded Eminger to the Florida Panthers in exchange for
Noah Welch and a 3rd round draft pick. On September 4, 2009, Eminger was signed as a free agent by the
Anaheim Ducks on a two-year deal. On July 9, 2010, Eminger was traded to
New York Rangers for
Aaron Voros and Ryan Hillier. On September 10, 2012, Eminger agreed to a new contract with the Rangers. After spending his professional career entirely on North American soil, Eminger signed as a free agent to his first contract abroad with Russian club
CSKA Moscow of the
Kontinental Hockey League on October 21, 2014. After producing just 2 assists in 25 games, Eminger was released from his KHL contract, and on January 24, 2014, Eminger joined the
Norfolk Admirals after having cleared AHL waivers. On September 5, 2014, the
Boston Bruins announced that Eminger had signed a one-year contract with their AHL affiliate, the
Providence Bruins. As a free agent in the summer and into the midpoint of the
2015-16 season, Eminger returned to play, signing a professional try-out contract with the Lake Erie Monsters of the AHL on January 21, 2016. Eminger ended his playing career after winning the
Calder Cup with the Monsters during the
2015–16 season. On June 14, 2017, Eminger was announced to have accepted a position as a professional scout for the New York Rangers. ==Personal life==