Ghana coach Kwesi Appiah has revealed he is to introduce a tougher code of conduct for the national team's players following events at the World Cup.

Appiah sent Sulley Muntari and Kevin-Prince Boateng home early from the tournament in Brazil for physical and verbal assaults respectively. He said: "Players who come in will be made to sign contracts to forestall any problems like those in Brazil. "The contracts will spell out clearly camp rules and all other conditions."

Muntari and Boateng were suspended indefinitely for their behaviour and told to leave the camp before Ghana's last group match against Portugal, which ended in a 2-1 defeat and elimination from the tournament.

Appiah, who has been backed by the Ghana Football Association (GFA) and is set for a contract extension, added: "As we look ahead, I will look for committed players and we will try not to tolerate indiscipline and anyone who will bring our efforts down."