John Barnes says the arrivals of Thiago Silva and Edouard Mendy have given Chelsea confidence.
The Blues are unbeaten in 11 matches, raising hopes among fans that their side could challenge Manchester City and champions Liverpool this season.
Former Liverpool star Barnes, who lived in west London as a child, believes the signings of keeper Mendy and veteran defender Silva have made all the difference.
And he says the impact is similar to the difference Virgil van Dijk and keeper Allison made at Liverpool.
Speaking to BonusCodeBets, Barnes said: “Both Thiago Silva and Mendy have given the Chelsea team confidence.
“Regardless of their ability, they have come in and settled everyone’s nerves – like when Virgil van Dijk and Allison came to Liverpool a few seasons ago.
“They are great players, but everyone became more confident because of their presence and given the whole squad a sense of security and they are showing what they can do.
“Thiago has that same presence at the back for Chelsea and you can see what it has done for the other defenders alongside him.”
But Barnes believes Chelsea’s defending does still need to improve.
“They have still given opportunities for teams to score, the likes of Burnley, so they haven’t necessarily turned a corner and won’t be winning every game,” he said.
“They are certainly moving in the right direction and made a lot of improvements.”