Former England coach Gary Neville believes Chelsea are missing a winning mentality.
Goals from Richarlison and Gylfi Sigurdsson saw them beaten 2-0 by Everton at Goodison Park, which could prove a huge blow in their bid to finish in the top four.
“If they win, they go and score two goals in the first half, you say it's a masterclass of a performance - they've controlled the game," Neville said on his regular Sky Sports podcast.
“They lose and you start to think of them as being a little bit nice, a little bit passive.
“They've just not got that edge, something that makes that game in the first half two and three-nil.
“You think of [John] Terry and [Didier] Drogba and [Ricardo] Carvalho and that type of player that existed at this club. Diego Costa.
“They just lack that little bit of something and when you watch them today, it's a team that's evolving, it's a team that's obviously different than how it's been in the past, they play a lot more passes, the centre-backs split to five yards off the touchline when the goalkeeper has the ball - it's not something we've seen before."