Gordon signed from Hearts back in August 2007 for £9 million, a British transfer record fee for a goalkeeper.
The former Scotland number one made 95 appearances for the North East side in five years, however his time at the Stadium of Light was beset with injuries and a lack of form.
Gordon broke his arm twice and then was hit with a knee tendon injury and anterior cruciate ligament damage, which ruled him out for eight months back in April last year.
With Belgian Simon Mignolet as Sunderland’s regular number one and Keiren Westwood battling for the jersey, Gordon’s time at Sunderland was up as his contract runs out.
After Sunderland manager Martin O’Neill called time on Gordon’s career at the Stadium of Light, the keeper has once again been linked with a move back north to SPL champions Celtic.
The newly-crowned champions are currently weighing up a permanent move for Newcastle United loanee Fraser Forster, but with Gordon a free agent and only his wages to take on, Celtic could make their move for the keeper safe in the knowledge that they have the experienced Zaluska on their books, along with American Dominic Cervi in the wings.