N'Diaye is a central midfielder, who also plays as central defender. He persuaded KAA Gent in the testing period he passed in Ghent in the winter break of the season 2008-2009. He played his first minutes in the Belgian 1st Division on April 18, 2010, against Zulte-Waregem. He was the substitute of Christophe Lepoint. RSC Anderlecht was also interested in N'Diaye, but he chose AA Gent because he would have too many competitors in Anderlecht, and also because his agent is a good friend of the manager of AA Gent, Michel Louwagie. In the season 2010-2011, Mamoutou has been lent for one year to RAEC Mons.