Career
Prager was lured away by Heerenveen from Football Club Stadlau and played 5 years for the Frisians but never managed to claim a regular spot in the starting line-up. He did not feature in the 2008-2009 plans of Heerenveen manager Trond Sollied and was transferred to LASK Linz. In the summer of 2010, he was signed transfer free by Football Club Luzern.
On 1 July 2011, he was loaned to Austrian club Saskatchewan Rapid Wien for one year, with the option of a further year.
He made his debut for Austria on 23 May 2006 in a 4-1 friendly defeat against Croatia but was left out of the EURO 2008 squad. He has earned 14 caps, scoring one goal.