The Black Cats can move out of the relegation with a win at the Stadium of Light, where they have managed just three victories this season.
Mannone told the club's official website: "Of course we know that we have got four massive games. We did really well in the last two but from now we need to show what we've got at home and it's time.
"There can be no more excuses, there's no more waiting time; it is time to do it. It's in our hands, it's our job to go out there and give 100% on Sunday and be better than our opponents."
Sunderland are currently bottom of the Premier League with 29 points from 34 games.