Blues boss Antonio Conte declared the title was out of their grasp after losing to West Ham last Saturday. However, Chelsea bounced back with an impressive 3-1 win over Huddersfield on Tuesday.
And 1998 World Cup winner Desailly believes the players must continue to build their confidence and momentum before facing the 5-time European champions.
“Chelsea lost to West Ham recently so the side is not in the best shape,” he added. “They need to use the league to psychologically recover from this defeat and be in good shape come February when the Champions League starts [again].
“They can then recover from the past mistakes and show they have the capacity to become one of the leading sides in England and Europe. From what I have seen I think Manchester City have something more than any other team in Europe today. You see that by their 11-point lead on all the others.
“Maybe their dominance now won’t be the same in February. Napoli were like City earlier [in the season] but they have since dropped physically and then dropped points so I think everyone is hoping City have that [kind of] drop so they won’t be this good in every game.
“Last season was the best season for Chelsea to win [the title]. City weren’t that good, they weren’t ready for the philosophy of Pep Guardiola. Manchester United were not at the top level and didn’t have all the top players. Tottenham didn’t have enough of a winning mentality.
“Arsenal have always had problems during the season, so last season was a special year for Chelsea to win it. This season there’s a lot of new players; Alvaro Morata, Tiemoue Bakayoko, Danny Drinkwater and Davide Zappacosta.
“Even Marcos Alonso, Andreas Christensen and Victor Moses coming in, they need to maintain their level across more fixtures. That can be the difference but it is just a matter of time to get back to that level that they had before.
“Bakayoko has not given his full potential. Nemanja Matic was already comfortable at Chelsea and was embedded in the system so it was easier for him but I think that they potentially have the squad to win things. Willian and Pedro want to be in their national squads for Brazil.