Ghana coach Ratomir Dujkovic refused to name names but was left unimpressed by some of his players after their 2-0 World Cup debut loss to Italy.
But he also conceded their opponents were the superior team in Hanover.
"They were very good," Dujkovic said. "All the stories (on match-fixing) in Italy at the moment have not affected them. They deserved to win.
"Maybe we had some chances but we missed. With one group of players I'm satisfied, with another I am not."
Ghana's next match is against the Czech Republic, who top Group E on goal difference from Italy.
But Dujkovic remains buoyant that Ghana can bounce back and get their campaign rolling in Cologne on Saturday.
"We lost one match and now we'll try to win the next," he added.
"Of course the players are a little bit disappointed but they need to keep their chins up and focus on the next game.
"I still believe that we can progress to the next stage even though the Czech Republic beat USA 3-0.
"I have confidence in my team, I have faith in my players."