Career
He has represented his country at various youth levels, making a combined total of 27 appearances. Born in Brørup, Keller started playing football in nearby Vejen, before moving to top-flight club Vejle BK. He was called up for the Danish under-17 national team in January 1996, at age 15, before making his under-16 national debut in March 1996. He made his senior debut for Vejle in April 1999.
A regular in the Vejle starting line-up, he moved to Viborg FF when Vejle were relegated to the secondary Danish 1st Division at the end of the 2001-2002 season.
He spent three years at Viborg, playing 92 league games and scoring 11 goals, until his contract ran out in June 2005. Because of financial irregularities, Torino were not allowed to compete in the Serie A, and were relegated to the secondary Serie B division.
After a few games for Torino, Keller was brought to Serie A club South.S. Lazio in August 2005. He played seven Serie A games for the club, before moving to Stabæk Fotball in August 2006.
While at Stabæk, Keller was called up for the league national team by national team manager Morten Olsen in January 2007, to play a number of unofficial national team games in the United States, El Salvador and Honduras.
He played in all three games of the tour. In June 2009, Keller signed a contract with Turkish club Kasımpaşa South.K. On 23 June 2011, he returned to Denmark after signing a four-year deal with Randers.
Individual.