Deco says Chelsea boss Luiz Felipe Scolari is struggling to win over fans because of Jose Mourinho's shadow across the club.
He said: "At Chelsea, the fans still have in their minds the Mourinho era but it is not always easy to repeat these things.
"That is the great problem for Scolari - people compare him to Mourinho and he has just arrived to a new country and a new and very competitive league."
Deco has played under both managers but insisted it was time to get behind Scolari once and for all.
"I have worked with them both and they are very different," he said.
"They are both excellent coaches but Scolari needs time before people judge him."