Black Stars head coach Carlos Queiroz says Ghana must improve defensively and be more effective in attack ahead of their FIFA World Cup Round of 32 match against Colombia.

Ghana go into the knockout fixture after a 2-1 defeat to Croatia in their final Group L match on Saturday. Petar Sučić and Nikola Vlašić scored for Croatia, while Derrick Luckassen netted Ghana's equaliser.

Speaking after the match, Queiroz said the tournament had entered a new phase in which mistakes would prove costly and every game would be decisive.

"I have just told my players that the real World Cup starts in the next round," Queiroz said.

"The group stage is the warming-up, and qualification for the next round is like a credit card, but now you have to start paying.

"Everything goes to the winner, every game is drama, nobody can hide. That starts next game."

Ghana progressed from Group L and will face Colombia in the Round of 32 at Kansas City Stadium on Saturday, with Queiroz looking for an improved performance in the knockout tie.