Career
Berggreen made his debut in the Danish first-tier for Hobro IK during the first half of the 2014-2015 Danish Superliga season. On 9 September 2014, he made his debut for the Danish U21 national team, and became the first Hobro player to ever represent a Danish national team at any level, scoring a goal in his debut. On 31 January 2015, he signed a 2 1⁄2-year contract with German 2.
Bundesliga club Eintracht Braunschweig.
On 8 February 2015, Berggreen made his debut for Braunschweig. He came on as a substitute in an 0-2 defeat on the 20th matchday against 1.FC Kaiserslautern, coming off the bench in the 69th minute for Raffael Korte.
On 23 February 2015, made his debut in the starting line-up, in a 1-1 draw on the 22nd matchday against RB Leipzig, also scoring his first goal for Eintracht Braunschweig. On 25 May 2015, he came on as a substitute on the 31st matchday against FSV Frankfurt and contributed two goals to the 2-0 victory of his team
He moved to Mainz 05 on 31 January 2016.
