Former Chelsea midfielder Frank Lampard is concerned the Blues are lacking "real personalities" and believes their current Premier League position is "ridiculous".
Under the leadership of interim manager Guus Hiddink, Chelsea have put a poor start to the season behind them.
They are still in the Champions League and the FA Cup, while Saturday's win at Southampton lifted them to 11th in the Barclays Premier League.
However, former England international Lampard, who played more than 400 games for the club between 2001 and 2014, sees John Terry as the last of the big personalities at Stamford Bridge.
He told the Mail on Sunday: " I do worry about where the real personalities of the team are. To be a big team, you have to have big personalities.
"I don't want to sound like I am harking back to the days of me and John (Terry) and Ashley Cole and Petr Cech and Didier Drogba but I do see a team now where John is the last mainstay of that identity.
"Maybe Chelsea are looking for a more beautiful way now. The club has been trying to push it down that route with the players they have recruited over the last four or five years.
"The problem is if you fall in the middle, somewhere between tough and beautiful. It's nice football at times but it's not that nice and it's not really winning games. It's not beautiful, beautiful stuff.
"They need to buy two or three big players. Because being 11th in the Premier League is ridiculous for Chelsea."
Lampard, who had a spell with Manchester City prior to his move to current club New York City, is tipping Pep Guardiola to impress when he takes up his post at the Etihad in the summer.
He added: "They will be a huge force under Guardiola. I think, yes, Man City can push on in a massive way. He's an innovator.
"There are two geniuses: Jose Mourinho and him. What a great rivalry that will be if Jose goes to Old Trafford."
Now 37 and preparing for a new season in the MLS, Lampard added: 'I don't know yet whether this will be my last year as a player - but whether it is or not, I don't want to go out with a whimper."