Fajdek represented Poland at the 2008 World Junior Championships in Bydgoszcz, finishing just off the podium in 4th despite throwing a new Polish junior record of 75.31 metres with the 6 kg under-20 implement. In 2009, his first year as a senior, Fajdek placed 8th at the European U23 Championships in Kaunas, Lithuania with a throw of 68.70 metres. Fajdek placed 3rd at the Polish Championships that year with a mark of 70.86, behind former Olympic and World Champion Szymon Ziółkowski and a returning Wojciech Kondratowicz. In 2010 he grabbed another national bronze, this time with a throw of 73.85 metres; later that year, he improved his personal best to 76.07, good enough for 35th in the world.