Ghana coach Kwasi Appiah has told his players not think about playing in the knockout stages if they are not prepared to battle against Niger.As the 2013 African Cup of Nations gradually nears second round, Appiah is aware that some members of his squad are on bookings ahead of their last Group B match on Monday but he wants them to be competitive as they come up against a very physical side.The Black Stars already have Mubarak Wakaso ruled out through suspension after he was booked for lifting his shirt to reveal a message when he scored in the 1-0 win against Mali.“Once you wear the jersey, you need to give off your best,” Appiah said on Saturday at his pre-match conference.“There are some things like taking off your shirt when you score, when you do that you will get a yellow card, you will be cautioned.“But as to going in for tackles, as a midfielder you just have to do that to make sure that you defend the flag of Ghana.”The Black Stars coach is however quick to point out that his players will be warned about not rushing into tackles.“They will all be cautioned as how you they go into tackles but for me having a yellow card does not mean you should go out there and relax. In that aspect, then it’s better you sit on the bench.”Ghana, tops the Group B standings with four points from their opening two matches ahead of their final group game in Port Elizabeth.