David Luiz has a long way to go before he can justify his £50m price tag at Paris Saint-Germain, according to Juninho Pernambucano.
The former Chelsea man has been criticised for a series of shaky performances since commanding a world-record transfer fee for a defender in the summer.
"David Luiz has not started his season as he should," the former Lyon playmaker told RMC. "Today, he still has not the form expected of him. I would not say it is bad.
"I watch PSG play. He commits mistakes from time to time but all the goals are not because of him.
"Maybe he should play Marquinhos. But this team does not live together. They are not able to play all matches at the same level. I do not know what happens."
Les Parisiens, who have won Ligue 1 in each of the last two seasons, sit third in the table, three points behind leaders Marseille.
