You need to win respect of rogues, or get someone like Vinnie to sort things

Another chance: Joey Barton

The clue is in a manager's job description. Yes, you have to be able to coach and you have to be able to spot good players but, above all, these days you have to be able to manage. It's the crucial part of the job and undoubtedly it has got harder.

The key is meeting problems head on; trying to see issues from a player's point of view. Some managers I could mention tend to hide and hope that problems go away. They won't.

Now it is time for Kevin to try to get inside Barton's head and for Roy to make sure Diouf doesn't upset what appears to be a good, tight dressing room at Sunderland.

The situations are slightly different in that Kevin has inherited his player from Sam Allardyce, while Roy has decided to buy Diouf. But the challenges are the same and I wouldn't have shied away from managing either player. My trick was always to try to get inside the player's head. To ask myself: 'If I was in his shoes, how would I feel about this? Would I even feel the same?'

Getting to know you: El-Hadji Diouf squares up to Atletico Madrid¿s Miguel Ferrer

Beyond that, you can only make sure the player is aware of his responsibilities and aware of the punishments if he does not meet them.

If a player knows he starts on the same footing as his team-mates - and knows you won't shy away from punishing any lapses - there is a much greater chance that you, as a manager, will earn that vital ingredient: respect.

If you have that, you have a fighting chance. You may put your arm around him, talk to him one-on-one - the other players don't have to know - and even turn a blind eye to the odd minor indiscretion. If you have respect, you can do that.

And remember, it can be useful to have a wildcard character in the team. Remember the likes of Eric Cantona and Paolo Di Canio - potentially difficult to handle but well worth the effort.

Triumph: Vinnie Jones wins the FA Cup with Wimbledon in 1988

One of the biggest problems in my career was the one I had with the Dutch marksman Pierre van Hooijdonk when I was at Nottingham Forest. I knew I had a problem with him when he told me very early on that he thought our left back was no good. That would have been OK, but our left back was Stuart Pearce! And he was the caretaker manager at the time!

Eventually, I failed with Van Hooijdonk. I listened to his early gripes. I even agreed with some of them. I gave him some leeway. But, ultimately, I failed because he had respect for nothing. Not me, not the club and not his team-mates.

Eventually, he went on strike. I should have gone out to see him in Holland. Instead, I did my  bidding on the phone. It was a mistake but would it have made any difference? Probably not.

Sometimes you just have to cut your losses and move the player on. If he will not come into line then you have to get rid before he poisons the atmosphere in the dressing room. No matter how good your players are, you will not succeed without basic harmony. That will be crucial to Kevin's chances with Barton and Roy's with Diouf.

If the players are a good, tight group, the potential troublemakers will more often than not fall into line. That is why Diouf did well at Bolton under Allardyce; the dressing room would not tolerate trouble.

At Nottingham Forest I suffered because I had no one to bring Van Hooijdonk into line. Geoff Thomas would have done it for me but unfortunately he was injured. Geoff was handy but I wouldn't have fancied his chances against the big Dutchman on one leg!

The other players there were just not strong enough.

I needed Vinnie Jones or John Fashanu from my Wimbledon days. They would have dealt with Van Hooijdonk in the crudest possible way.