The Quakers were relegated from the Football League after a poor season and manager Simon Davey has included both Coventry born Giddings and Rikki Bains in the cull.
Giddings made 22 appearances for Darlo after making 25 appearances for Hinckley United earlier this season.
Bains made his Darlington debut back in August 2009 and had three first team starts plus two substitute appearances. He has been loaned out to Blyth Spartans where he had five starts and Gateshead where he made four starts and a substitute appearance.