The return of N'Golo Kante will lead to an upturn in form for Chelsea, according to former Blues defender Marcel Desailly.
A hamstring injury sustained on international duty with France meant Kante missed six matches for Antonio Conte's side, who suffered defeats to Crystal Palace and Roma in that span.
With the dynamic midfielder back in the starting line-up against Manchester United on Sunday, Chelsea secured a 1-0 victory that moved them just one point behind Jose Mourinho's second-placed team.
Desailly, an FA Cup winner with the west London side in 2000, is predicting improved results at Stamford Bridge following Kante's comeback.
"It is not a coincidence. I did not see the game, but my friends told me he had a great game. [Chelsea] were in need of a player who can sit in front of the defence to help and block the opponent and bring that extra energy, to play the intervals, to start the actions," he told Omnisport, speaking at the Golden Foot Hublot Award in Monaco.
"I'm very pleased he's back. Psychologically, it's also a boost for the entire collective, because since he left, Chelsea have been on and off. Now, he's back and he stimulates the rest of the group."
"They don't have big individual players, but at least if collectively they are back to their original level of last year, then maybe Chelsea will be back at a certain level."
Head coach Conte has been tipped to leave Chelsea amid reports of strained relationships with those above him, and a move to AC Milan is among the most recent suggestions.
Desailly claimed he would not be overly concerned about the Italian moving on, as long as it does not happen before the conclusion of the campaign.
He said: "I just want him to finish the season. We want Chelsea to be at a certain level. Next year, it's the business which allows him to stay or go. That's not my problem.
"I want him now to bring back his philosophy and his cleverness. When he came, he really changed the system. Playing in England with three at the back was tough, with all of the space you leave on the wings. He managed to do it and win the league with it quite easily.
"He can do whatever he wants next year. We love him and another one will come. You don't look at the players or the managers, it's the club which is important."
