Thiago Silva has urged Chelsea to come up with a "strategy" to prevent the club's slump stretching into next season after Real Madrid ended their Champions League campaign.
The Blues' final hope of salvaging a disastrous season was snuffed out on Tuesday as the Spanish side wrapped up an emphatic 4-0 aggregate win in the Champions League quarterfinals.
Brazil defender Silva admitted the season had been tough for the club and said Chelsea's bloated squad ensured there were always unhappy players.
Chelsea have spent more than £500 million on transfers since a consortium led by Todd Boehly and Clearlake Capital Group bought the London club from Russian billionaire Roman Abramovich last year.
Frank Lampard, the current caretaker boss, is their fourth manager this term following the sackings of Thomas Tuchel and Graham Potter and one game under interim coach Bruno Saltor.
Lampard has lost four successive matches since returning on a temporary basis, with his side scoring just once in that period.
Chelsea are languishing in 11th place in the Premier League table – 17 points adrift of the top four – with seven games to go and are unlikely to qualify for European competition.
Silva, speaking after Tuesday's 2-0 home defeat to champions Real in the second leg of their quarterfinal, said it was important to assess what had gone wrong rather than apportioning blame.
"It is not enough to look at the coach, say 'it's this person's fault, it's that person's fault' if we don't assume our responsibilities," he said.
He added: "We have to stop and have a strategy to not repeat the same mistakes next year."
Silva, 38, said the club had been forced to increase the size of the changing room to accommodate their huge squad, with eight new signings in January alone.
"I think it is a difficult time for the club, with a lack of definition at the beginning, a change in owner, many players arriving – they even had to increase the size of the dressing room because there was not enough room for all the players," he said.
"A positive point is that there are great players in the team but a negative point is that someone is going to get upset, because not everyone can play and the coach has to pick 11 players and there are 30-something."