The latest high-profile departure from the Obama administration is Lawrence Summers, the head of the National Economic Council.

NPR: The Pressures Of Working In The White House

Cassidy has also insisted that the Derry squad is not in a state of disarray despite Paddy Bradley's high-profile departure from the squad.

BBC: Eoin Bradley wants brother Paddy back in Derry squad

Arnesen's resignation is the second high-profile departure announced by the club in a matter of weeks after long-serving assistant manager Ray Wilkins left earlier in the month.

BBC: Frank Arnesen resigns as Chelsea sporting director