... Keeps turning up late
Have clear rules about punctuality and attendance. The same rule should apply for all. Consistency is key, but leave room for flexibility. A one-on-one meeting will give the player a chance to explain himself. If he’s still unwilling to play by the rules, increase the punishment.
More after the break
... Questions your tactics
Do not engage in a debate with any player in front of the squad. Respond calmly and respectfully, but decisively. Players will smell insecurity. Be clear and confident about your ideas. If he successfully picks holes in your tactics you will soon lose the dressing room.
... Keeps getting sent off
The first time this happens, wait a day and then ask the player to explain what happened. Listen to his account and explain that his behaviour is unacceptable and damages the team. Get the player to repeat what you’ve told him so you can be sure that he’s understood the message.
... Goes out partying the night before a game
Speak to the player and administer a fitting punishment. If there were unique circumstances consider a degree of leniency, but be wary of upsetting other players, who might think your star man is getting preferential treatment. If this happens explain your decision to the captain, who can relay it to the team.
... Undermines his team-mates
Make it clear that you will not tolerate this attitude and by getting on the back of his team-mates he’s shattering their confidence. If they perform badly this weakens the team’s chances of winning. Does he want that? Tell him that you sympathise with his frustrations, but if he continues to discourage rather than encourage, he will be punished.
... Sulks when he’s having a bad game
Negative body language can be contagious. Don’t indulge his strop. Inspire with encouragement and then try to get to the bottom of it. Explain to the player that he has to accept he will not always play well, but he must work hard for the team.