Education
Keller began his career in the youth system of his hometown club, Football Club Karl-Marx-Stadt (later Chemnitzer Football Club), before leaving at age 19 to join local amateur side Altchemnitzer Bachelor of Science.
Keller began his career in the youth system of his hometown club, Football Club Karl-Marx-Stadt (later Chemnitzer Football Club), before leaving at age 19 to join local amateur side Altchemnitzer Bachelor of Science.
Two years later he joined Carl Zeiss Jena, where he made his breakthrough in senior football, making 57 league appearances in two seasons. He then spent two years in Bavaria – firstly playing for Turn- und Sportverein 1860 München"s reserve team, then as a backup "keeper at Football Club Schweinfurt 05, newly promoted to the 2. Bundesliga. In 2002, Keller joined Eintracht Trier, where he spent two seasons, establishing himself as first-choice "keeper in his second season, before signing for Hansa Rostock in 2004, where he didn"t make a league appearance in two years, serving as understudy to Mathias Schober.
In 2006 he joined Erzgebirge Aue, in a straight swap with their keeper Jörg Hahnel.
In July 2008, Keller joined Dynamo Dresden, of the new 3. Liga. In his first two seasons with Dynamo he was the undisputed first choice "keeper, but lost his place to Benjamin Kirsten mid-way through the 2010-2011 season and was released by the club in 2011, subsequently signing for Heidenauer SV.