The feisty central midfield combination were the foundation for Sunderland's impressive early season form, but the pair's influence has waned in recent weeks.

Cattermole suffered a knee injury in October, and although now back in the team, he has yet to hit top form.

Bruce said: "It's very difficult. I know from my own experience, if you miss a big chunk of the season through injury, it takes you, in my opinion, just as long to get back.

"If you are out for six weeks, it takes you six weeks to get back to where you should be.

"In Lee's case, there is no more genuine boy than he is and he is trying his utmost - and he will get there.

"The more games he plays, the better he will become."

Cana joined the club from Marseille and won rave reviews for his performances in the opening months, but his form has been lacking in recent weeks.

Bruce admitted: "It's caught up with him. It's the intensity because the adaptation from playing in France to here is huge.

"The intensity of the game in England is the one thing that takes some getting used to.

"But I have no problems with Lorik in terms of his commitment to the cause. I made him the captain and I have no regrets about that.

"Yes, he has suffered in the slump, if that's what you want to call it, but he will be okay, I am convinced of that."