However, the Everton manager also pointed out that it is not just the centre-backs who deserve credit for their three most recent opponents drawing a blank.

Silva said: "It shows one good thing for me: all of them are prepared to help the team and all of them know what is our defensive idea, that is a good sign for me as a manger.

"But for us to have a clean sheet we have to be a block and the block and good defensive organisation doesn't start with our central defenders or our goalkeeper or our lateral defenders.

"In our block we start with a good shape with our striker and normally the offensive midfielder in our model is the first player to start defending.

"It's part of the block and our idea is even if you are in an offensive idea, you can attack well if you are always in a good balance, being solid and that's everything that we've been doing in the last few games.

"It's something that has to be our aim to keep doing."

Keane was a late withdrawal from the side that defeated Arsenal 1-0 last Sunday, with replacement and club captain Jagielka scoring the winner, his first goal in almost two years.

Jagielka could immediately be dropped to the bench for this weekend's trip to already-relegated Fulham as Keane is back in training following illness, though Yerry Mina remains sidelined by a hamstring injury.

Silva is not underestimating Fulham, who are on their third manager of the season, with Scott Parker in caretaker charge following the February sacking of Claudio Ranieri, who himself took the reins from Slavisa Jokanovic in November.

Silva said: "I can see very good individual quality in their team, I don't have doubts about that. It's not easy when you change three times the manager, it's not a good sign.

"But we have to think in Fulham like we did against Chelsea, West Ham or the last game against Arsenal."

One player who has shone in Everton's recent run is Brazilian winger Bernard, who is starting to perform on a more consistent basis after taking time to settle at Goodison Park following last summer's switch from Shakhtar Donetsk.

Silva is a fan of the 26-year-old, who bagged his first league goal for Everton at West Ham last month, but wants him to find the net on a more regular basis.

Silva said: "You can see he's a fantastic football player, he can improve, for sure.

"He's a player more to assist but we want him more in those key positions where he can score more goals because it will be really important, and it is something I demand from our wingers."

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