Gordon has not played competitive football since April 2012 due to a serious knee injury, but he believes that people are wrong to suggest that he may not return to the top level.
"I feel I can take pride from the way I've worked hard to get back," the 31-year-old told the Daily Record.
"The majority of people have probably written me off by now, the perception being I'll not be back.
"There will be others who'll say I might not return but I will get back to my best. I'm willing to prove all those people wrong."
Gordon moved to Sunderland from Hearts in 2007 for £9m, which is a record fee for a British goalkeeper.