Former Chelsea midfielder Deco has claimed that "important players" in the Stamford Bridge dressing room spoke to the club's directors if they had complaints to make about the team's head coach during his time at the club.
In an interview with FourFourTwo magazine, Deco suggested Luiz Felipe Scolari's brief and unsuccessful reign as Chelsea manager was undermined by influential players, who he says voiced their complaints about his coaching style to the decision makers at the west London club.
Chelsea captain John Terry and former vice-skipper Frank Lampard have both in the past denied talk of players influencing big decisions made at the club, but Deco revealed that some members of the squad would go over their boss' head.
"The first four months we were leading the Premier League, but we had a lot of problems with important players after that," Deco said of the 2008-09 season. "Some players were not playing and it's really difficult to say what happened.
"He [Scolari] is an emotional coach who needs to talk and express his feelings to the players. He couldn't do that at Chelsea. Another thing was that at the time some players, if they had a problem with the coach, didn't speak to him but instead communicated directly with the directors. That isn't good for a team."
Deco went on to identify the best coach he worked under in a career that included spells under the guidance of some of the biggest names of this era in a career that saw him win trophies with Porto, Barcelona and Chelsea.
"I think the best coach is Jose Mourinho, but I had a lot of important coaches in my career," he said. "Fernando Santos was very important for me when I came to Porto at 19 years old. He taught me a lot of things that were important in the future.
"Carlo Ancelotti was a fantastic coach too, but I only worked one year with him. Scolari too, of course, but at that time Mourinho brought something different; he brought the ambition, because at that time in Portugal it was difficult for a club to think it could win the Champions League.
"Of course, Porto had won it in the past but it was a different time. After Bosman [ruling] it was easier for players to move around, and clubs like Barcelona, Chelsea, Madrid, Manchester United had money to buy the best players.
"If you play well for one or two years at Porto, it's very difficult for them to keep the players and therefore very difficult to win the Champions League. But Mourinho brought this confidence to us; we had a fantastic team and he gave us that final push to believe it was possible."
Deco picked out a Manchester United veteran as one of his toughest opponents, as he identified a player who is often hailed by rivals as an under-rated performer.
"Paul Scholes too was one of the best players I've ever seen," he said. "For me, he was one of the best midfielders in the world and in history. It's never easy in a big team, and he didn't score a lot of goals, but he organised the team fantastically. When a side has good midfielders with quality, it's easier for the attackers."
Brazil-born midfielder Deco played with Lionel Messi at Barcelona and Cristiano Ronaldo in the Portugal national team, and admitted it was tough for him to suggest one was more talented than the other.
"It's difficult to make a choice, not because I'm friends with both but because they're different," he said. "When you compare players like Cristiano Ronaldo and the Brazilian Ronaldo, or Messi and [Diego] Maradona, it's a bit easier because they are similar players, but it's difficult with these two because they are so different.
"The goals that Cristiano scores, Messi doesn't score, and goals that Messi scores, Cristiano doesn't. Messi has the talent he was born with. Cristiano also has talent but it's unbelievable how hard he has worked, how professional he is. You [fans] can choose because you like one more than the other, but you can't say one is the best."