The 26-year-old Scotland international, the club's record signing when he clinched a £9m switch from Hearts in August 2007, is already back at the club's Academy of Light training headquarters as he recovers from knee surgery.

Gordon underwent an operation in May after a frustrating season had been brought to a premature end by the problem after already missing much of the campaign with an ankle injury.

Hungarian Fulop was the main beneficiary of the Scot's misfortune with the Edinburgh-born player managing only 14 appearances.

He has been linked with a move away from Wearside this summer, but all he is currently concentrating on is regaining full fitness and restoring himself as first-choice keeper at the Stadium of Light.

Gordon said: "After starting last season fairly well, it just fell away after that and it was just one thing after another for me. I have not experienced that before in my career, but hopefully I have got all that out of the way at the same time and I can concentrate on getting fit and healthy and have a good run at it this season.

"It was a new experience for me and it was difficult to handle, but these things happen over the course of a player's career and it's about bouncing back and handling it, coming back fitter and stronger and ready to go again."