The European champions were beaten 1-0 by South American title-holders Corinthians in the final of the Club world Cup on Sunday prompting Brazilian forward to be critical of his Blues mates.
"It seems that some people are missing a few things, principally the desire to be champions," Piazon told www.esporte.uol.com.br.
"I think Ramires and David Luiz, the Brazilians, were the ones who strove to give their utmost, and are therefore the ones who are most upset.
"We lacked character and a love for the shirt. Nobody wanted the ball. At least Oscar tried.
"I won't be more specific but I can say that the team lacked willing. You don't go into a final without the desire to play the ball, that's unacceptable."