Frank Lampard has praised the influence of duo Edouard Mendy and Thiago Silva on the Chelsea side since their summer arrivals.
Mendy arrived from Rennes for £22 million while Silva joined on a free transfer after leaving Paris Saint-Germain.
The pair have played five times together on the pitch and Chelsea have kept a clean sheet on each occasion - the most recent in the 3-0 win against Burnley at Turf Moor on Saturday in the Premier League.
Chelsea are now in fourth in the Premier League and boss Lampard believes the duo have had a great impact on the side.
"The clean sheets are a great sign of a spine in the team. Thiago Silva and Edu Mendy have massively helped that but so has the mentality of the group with the way we’re defending.
"I’m not going to jump up and down after a win like this but it was a really positive day."