RMC pundit Daniel Riolo believes his €100 million fee is weighing heavily on the Frenchman.
Riolo stated: "We do not see enough qualities in relation to his status and price. The price has an impact in the minds of players. He cannot be insensitive psychologically for what he cost.
"It will necessarily take time to digest this transfer. This remains a human being. At the time, the large transfers were made on players who had already proven themselves. Today, money is spent on the players who have not yet been proven.
"It's an investment on potential."