In probably their poorest performance of the season, Chelsea were well beaten by an Arsenal side as goals from Alexandre Lacazette and Laurent Koscielny gave the Gunners just their second victory in 14 meetings with their rivals.
Sarri’s side are now just three points clear of both Arsenal and in fourth place, and the Italian let his players know their performance was well below the level he deems acceptable.
‘I’m extremely angry, very angry indeed,’ he said after full-time, speaking in Italian and using his interpreter to ensure his message got across.
‘This defeat was due to our mentality. I can’t accept it. We had a similar issue against Tottenham in the league. It appears this group of players are extremely difficult to motivate.’
‘From a technical point of view both teams were on the same sort of level, but they had a higher level of determination in both penalty areas, so tactics don’t come into it. I can’t possibly say I am not partly responsible for the defeat. We have to share it.
‘This is not a team that is going to be well known for its battling qualities, but we need to become a team that is capable of adapting, possibly suffering for 10 or 15 minutes, and then playing our own football. Today we didn’t play our own football.’
The Blues have now lost two and drawn one of their past six Premier League matches, leaving them 13 points behind leaders Liverpool.
Sarri enjoyed a brilliant start to life in England as his team went unbeaten in the league until mid-November.
But their title charge began to unravel when they were beaten by Tottenham at Wembley and following another defeat Sarri questioned his players’ mental strength.
‘It seems to me that, as a group of players, they’re not aggressive from a mental point of view. They don’t have a ferocity in their mentality,’ he said.
‘That’s down to their characteristics. It’s difficult to change. It could take some time, or it could change with a new player coming in or an older head assuming more responsibility and driving the team on.’
He added: ‘I’m aware this is never going to be a team well known for its battling and fighting qualities. Those aren’t the characteristics that we have.’