 On 10 August 2015, Frederiksen was dismissed by Esbjerg with the side placed last in the Danish Superliga table after four matches into the 2015–16 season, with chairman Søren Poulsen citing "lacking" domestic results as the reason behind the dismissal.Frederiksen was succeeded by Jonas Dal.In August 2015, Frederiksen was named manager of the Denmark under-21 team, signing a two-year contract.