Sunderland goalkeeper Vito Mannone has hailed the John O'Shea and Wes Brown defensive partnership.
Mannone says it's crucial the former Manchester United duo remain.
"They have been massively important and you can see that they are so solid," the goalkeeper said. "We have a good relationship and it's always easy to play alongside them because they have experience and can read the game.
"Hopefully they can play for a long time.
"They have been leaders, but we have a few in the team. Of course (Brown and O'Shea) bring great experience with great careers and achievements, and we can rely on them."
