The former Brazil international worked under Luis Felipe Scolari, Guus Hiddink and Carlo Ancelotti during his two-year spell at Stamford Bridge which led him to question the authority inside the club. And the 35-year-old believes Abramovich took a "supporter's point of view" more often than a professional one.
"Chelsea is the only English club which is like that," Deco told reporters. "In other clubs managers have more power to decide, more time to work. I have stayed there since Peter Kenyon left and things have changed a bit since then. "
Deco added, "I am not sure how things work there, don't know if Abramovic takes all the decision. But obviously if you are the owner sometimes you have more a supporter point of view than a professional one. I had 3 different managers there, Scolari, Hiddink and Ancelotti, but definitely it is a atypical club, out of English custom."
The former Porto and Barcelona midfielder has also backed Jose Mourinho to return to Stamford Bridge six years after his dismissal as it will now represent a fresh challenge for the Portuguese.
"It is very difficult to speak about it because of the people involved," he explained, "I met him in December in Madrid, but we did not have much time to talk. But I don’t see it as the same challenge. It will be a new one. He would get a Chelsea trying to build a new squad.
"I don't know if he will go or not, but don’t see it as the same challenge just because it is a club where he already worked for. Even because if he works for more 20 years, he will definitely need to repeat some clubs."