Chelsea goalkeeper Thibaut Courtois believes the Blues were right to sack Jose Mourinho in December.
The Portuguese tactician led the club to the Premier League title last season but oversaw a disastrous start to the current campaign.
Chelsea were widely predicted to retain their crown but lost nine of their opening 16 top-flight games, which left the west Londoners languishing in 16th place in the table.
Such a poor run of results culminated in Mourinho's exit and Courtois is adamant the club had no choice but to bring an end to the 53-year-old's reign.
The Premier League defeats which cost Jose Mourinho his job at Chelsea
"It is hard to explain why our season has been bad," Courtois told Belgian television station RTBF.
"Maybe it is as a result of our pre-season preparations, which were very brief.
"We weren't in a good physical shape. We then lost to Arsenal in the Community Shield and went on to make a bad start in the league.
"A downward spiral set in. We needed a change of manager at that point - I have no doubts about it," he added.
Chelsea's form has improved since Mourinho's departure and the club are now unbeaten in 14 games since Guus Hiddink took charge on an interim basis.
The club are currently 10th - 10 points adrift of the Champions League places - with eight games left to play.
