Career
He made his debut for AaB in the Danish Superliga when he was in the lineup against Football Club Midtjylland on 4 April 2012. Nicolai Thomsen got his first international appearance on 1 March 2011, when he played for Denmark U-18. Since then, he has played for U-19 and U-21, before getting his first match for the Danish national team on 18 November 2014 against Romania.
Thomsen scored the only Danish goal in the 1-1 draw against Iceland which qualified Denmark U-21 for the 2015 Union of European Football Associations European Under-21 Championship.
He was in the line-up in the other two group stage-matches against Germany and Serbia. Thomsen was also chosen to the line-up in the semi final, where Denmark was defeated by Sweden.