Chelsea coach Maurizio Sarri has once strongly criticized his players and questioned their motivation.

Sarri watched from the sidelines as Bournemouth scored four second half goals to condemn Chelsea to a humiliating 4-0 defeat in the Vitality Stadium in which was their worst league defeat since 1996.

It's Chelsea's second league defeat in two games and follows their 2-0 loss away to Arsenal after which the Italian questioned his players' motivation.

The former Napoli boss adopted a similar tone following Wednesday's humiliation, which must also raise question marks over his own future at the club after fans sang "you don't know what you are doing", following his decision to substitute debutant Gonzalo Higuain.

After the final whistle Sarri locked the players in the changing room for an hour and spoke to them along after asking the rest of his coaching staff to leave.

"At that moment I wanted to talk to them alone, without anybody," Sarri said to the press.

He explained his decision by saying he "needed to understand" the performance and why the first and second halves were "so different."

"In the first half we could never see that the second half would be a disaster. We stopped playing. We didn't play like a team. It's difficult to understand why."

"I'm not able to motivate these players. We need to play with a different mentality," he lamented for the second consecutive league match.

The defeat sees Chelsea drop out of the top four, but the Sarri said he "thought" they were good enough to qualify for next season's Champions League.

"But we cannot lose 4-0 to Bournemouth," he concluded.