Chelsea have kept five consecutive clean sheets since the 3-3 draw against Southampton at Stamford Bridge.
The Blues had the worst defensive record among the top 10 Premier League teams last season and struggled defensively in the beginning of the season.
Asked the reason behind the improvement in Chelsea’s defence, Chelsea boss Frank Lampard said: “There’s always differerent parts to it. Individuals have made good performances in that period.
“The collective is reflection of that. It’s driven by the players, always will be. We must never relax. It’s such an important part of the game.”