korb played in tus preußen vluyn, hülser sv und djk/vfl tönisberg youth teams. in 2004, korb joined msv duisburg youth academy, and two years afterwards, in 2006, korb joined borussia mönchengladbach youth academy. he then spent the next five years developing in gladbach's academy, before making his debut in a senior game in january 2010, with the b team of gladbach.