The 23-year-old Belgium international has played in all seven of the the Black Cats' Premier League games to date this season.
It has proved a difficult start to the campaign for both Mignolet and Sunderland, but the former Sint-Truiden player is confident he has more to offer.
He told the Journal: "I'm still learning because it's only my second season and I hadn't played 30 [Premier League] games until the West Bromwich Albion game.
"I just want to look to myself, try and improve every day and work hard in training. Then we will see what's going to happen."