Mannone thinks the side has become more solid because of the manager and the recent additions.
Mannone also commented on manager Sam Allardyce's attributes of getting the side out of trouble, citing his experience as exactly what is needed at this stage of the season.
The Italian is quoted in the Northern Echo, saying: “The manager knows what to do because he’s been in the Premier League for 20-odd years. We’ve been working on defending properly a lot, and on doing the basics right.
“He is quite hands-on on the training pitch, and we always have a day or two during the week where we work on the defensive bits.
“To have the same people in their roles helps a lot. It helps when you are not changing every few games because it is difficult for whoever comes in.
“It is not nice to come in and not know each other, and it is not nice for who is there already and who needs to help the team-mate that is just coming in as well as focusing on their own game.
“All the new team-mates who have come in have helped. They have all been brilliant and made a difference. Each one is giving the right performance every game, and the right help. They have made us much more solid.”
Lamine Kone has been a rock at the heart of the Sunderland defence alongside either Younes Kaboul or John O'Shea, while Jan Kirchhoff has offered the back four some invaluable protection in particular.
The Black Cats have become a harder side to beat, and one can see the traits of a typical Allardyce side from a defensive point of view - they are not the easiest of sides to break down.
However, with the side having slipped back into the relegation zone following the weekend's results - albeit with a game in hand on Newcastle United who are a point ahead of Sunderland - there needs to be more than just solidity between now and the end of the season.
But given that Sunderland have shown they are hard to beat in games, and have this kind of resolve, that is half of the battle won, they just need to do the other part of getting wins on the board.