Former Chelsea striker Didier Drogba believes manager Jose Mourinho's influence waned during his first spell in charge while another ex-Blues boss, Andre Villas-Boas, was always set to struggle at Stamford Bridge due to his mismanagement of the club's senior players.
Mourinho's second spell in charge of the Blues has taken a dramatic turn for the worse this season, despite winning the Premier League title last term.
Chelsea have lost seven of their opening 12 league games and sit 16th in the table, while questions have been raised over the Portuguese's future at Stamford Bridge.
Reports have suggested that Mourinho had lost the dressing room, and Drogba, who ended his second spell at Chelsea in the summer to join Montreal Impact, revealed the Portuguese struggled to get his message across to the players during the end of his first reign.
"I believe things often come in three-year cycles [and] we had arrived at the end of such a cycle," Drogba is quoted by the Daily Mirror as writing in his new autobiography "Commitment."
"By the start of the fourth [season] that Jose had been in charge, I think we had started to reach a point where it was sometimes harder for his message to get through.
"We wanted to hear it, we tried, but somehow we had lost a little bit of what made us special."
Drogba also touches in his new book on the short reign of Villas-Boas at Chelsea -- the Portuguese was sacked just nine months after his appointment.
The Ivory Coast international felt Villas-Boas was doomed from the start after believing he could phase out key senior figures such as Frank Lampard and Ashley Cole.
"That's his right, because the club needed to keep moving forwards, but he shouldn't have kept those players at the club while he was trying to make his revolution," Drogba wrote.
"Although we weren't going around complaining, it had an impact on the rest of the squad if we weren't happy."
Drogba added: "Andre's mistake was to think that it was going to be easy -- that we just had to do things his way and we would win.
"You have to be able to listen [to experienced individuals] and communicate with them. Otherwise, if you manage a team like Chelsea, you're heading for a fall."