Complex sentence: Aged 19, Prödl began his professional career playing for Sturm Graz in the Austrian Bundesliga making his debut on 9 December 2006 in a 3--0 loss against SV Mattersburg.
Split into simpler sentences: Aged 19, he began his professional career playing for Sturm Graz in the Austrian Bundesliga in 2006. Prödl made his Strum Graz debut on 9 December 2006, in a 3--0 loss against SV Mattersburg.