Background
Danish-born January Popiel was drafted tenth overall in the 1964 National Hockey League Amateur Draft but grew up in and became a citizen of Canada before making his pro debut).
Danish-born January Popiel was drafted tenth overall in the 1964 National Hockey League Amateur Draft but grew up in and became a citizen of Canada before making his pro debut).
He was drafted by the Saint Louis Blues in the first round, 13th overall in the 2007 National Hockey League Entry Draft. In the 2007 National Hockey League Entry Draft, he was drafted 13th overall by the Saint Louis Blues. Eller spent part of the 2007-2008 season with Borås in the HockeyAllsvenskan, on loan from Frölunda.
Eller moved to North America for the 2009-2010 season.
His preseason was spoiled by mononucleosis and, as a result, he started the season in Peoria. He was called up by Saint Louis and made his National Hockey League debut on November 5, 2009 in a game against the Calgary Flames in which the Blues lost 2–1.
He scored the only Blues goal, beating Miikka Kiprusoff off of a deflection and had three shots on goal in 9:42 minutes of ice time. Eller appeared in five National Hockey League games before returning to the Peoria Rivermen, finishing the season with seven games for the Saint Louis Blues.
In Peoria, Eller was named AHL Rookie of the Month for the month of March and was also selected for the 2009-2010 AHL All-Rookie Team.
On June 17, 2010, he was traded by the Blues to the Montreal Canadiens, along with Ian Schultz, in exchange for goaltender Jaroslav Halák. In the 2010-2011 season on November 24, 2010, Eller scored his first goal with the Canadiens, wristing one past Los Angeles Kings goaltender Jonathan Bernier. On January 4, 2012, Eller scored 4 goals and an assist in a 7–3 victory against the Winnipeg Jets, his first career hat trick.
He was the first Montreal Canadien to score 4 goals in one game since January Bulis in 2006.
During the 2012-2013 National Hockey League lockout, Eller signed a temporary contract with Finnish top-flight club, JYP Jyväskylä. He recorded 5 goals and 10 assists in 15 games.
On May 2, 2013, an open ice check from Ottawa Senators" defenseman Eric Gryba knocked Eller unconscious during a playoff game at Centre Bell. He was later diagnosed with a concussion, along with dental and facial damage.
On July 24, 2014, he signed a four-year contract worth $3.5 million per year to stay with the Canadiens.