Sunderland boss Chris Coleman on whether Watford target Didier Ndong will be involved at Cardiff City

Watford want to sign the midfielder, who cost Sunderland close to £14million from Lorient 18-months ago, on a loan deal until the end of the season.

Sunderland have turned that offer down because Coleman says it doesn't benefit the Black Cats.

Coleman will assess Ndong - back in training after an ankle injury - to see whether he is "mentally ready" to be involved at Cardiff City given the January interest in him.

"Didier has trained this week and trained well. We will have a conversation with him," said Coleman.

"It will depend on where he is mentally, I think. He knows all about Watford.

"But the deal is not right for us. If I think he is not mentally ready then I can't afford to take him with us, not for a tough game like this.

"He has trained well, strong training days. It depends where he is mentality."

There is January interest from Premier League clubs in Ndong and defender Lamine Kone - both of who have stated they no longer want to play for Sunderland.

Coleman added: "We have had no contact for any of these players except for Ndong, that was a loan deal we are not prepared to do because we stand to get nothing out of that.

"We have had a couple of enquiries about Didier but loan deals won't work for Sunderland football club. That's where we are.

"Let's establish who definitely wants to be here, no pretenders and then lets build with a group of people who are in it for the right reasons and give everything from now until the end of the season.

"Didier has said he doesn't want to be here, Lamine has also said he sees his future elsewhere, which is fair enough.

"Nothing we can do about that until somebody comes in and says 'there you go, we want this player'. We are waiting for that to happen.

"In the meantime we want to try and bring in the players who see this as a challenge and want to help us out in what we are trying to do. Both things are running parallel."