Chelsea manager Antonio Conte reportedly launched a furious tirade at his players after they suffered a shock defeat to Crystal Palace on Saturday.
The reigning Premier League champions took on a side that had lost all seven of their games and had not mustered a single goal during that time.
Despite the Eagles' poor record, Chelsea were beaten 2-1 at Selhurst Park - their third league defeat of the campaign.
According to The Telegraph, after the final whistle Conte verbally ripped apart his players in the dressing room, warning them that they will not taste success this season if they do not work harder on the pitch.
The report also claims that there is concern behind the scenes with regards to the team's injury woes, with key players Alvaro Morata, N'Golo Kante and Victor Moses all suffering problems.
The intense training sessions, as well as additional games due to Chelsea being involved in all four competitions, is believed to be contributing to the growing injury list.
Next up for the Blues is a Champions League Group C match against Roma at Stamford Bridge.
