Maurizio Sarri held a meeting with his Chelsea players at Cobham on Monday after accusing them of being "extremely difficult to motivate" following their 2-0 defeat to Arsenal, sources have confirmed to ESPN FC.
Speaking in his native Italian in his postmatch news conference via a translator, Sarri said his team will never be known for its "fighting qualities" and accused his players of being "not particularly aggressive from the mental point of view."
Sarri also signalled his intention to hold talks with his players, both individually and as a group, about where things went wrong.
"I think the best thing that can happen is that the players and I talk very openly," he said. "We have to talk openly about what's happening.
"I am the person responsible for the team, of course. So that means we need to discuss the matters, we have to talk about issues, and it is important my players have the attitude I am asking them to have.
"If they don't have that, then maybe they shouldn't be playing at this level."
Sources have told ESPN FC that Sarri gathered his Chelsea squad together prior to Monday's training session at Cobham to discuss the Arsenal defeat.
Chelsea's players are believed to remain broadly supportive of Sarri, although the Italian's tactical stubbornness -- not least his continued deployment of Eden Hazard as a False No.9 -- has caused concern both at Cobham and among the club's fanbase.
It is hoped the imminent arrival of Gonzalo Higuain on loan from Juventus will solve that problem, with the Argentina international expected to be registered in time to be eligible to play in Thursday's Carabao Cup semifinal second leg against Tottenham at Stamford Bridge.