Former Chelsea star Emmanuel Petit believes manager Mauricio Pochettino has some unhappy players.
Chelsea go to Tottenham on Monday.
Pochettino told OLBG: "The confidence that Ange Postecoglou has instilled in the players is amazing, especially in midfield. You can see they play as friends and they're enjoying their football - and that's so important.
"It's impossible for every player to always be happy, but you must work at it.
"Pochettino has tried to get that with his team, but I'm not sure how many players are arriving with a smile on their face.
"Chelsea are struggling and the manager is struggling to put his vision on the pitch.
"Compare that to Tottenham. You can see the support from the managers and the players. They're enjoying it, and that's so important for me."