"We want to improve our power in attack, this is our idea," said Benitez.
"There have been games in the past we have played with three centre backs and two offensive full backs, it depends on the game.
"But normally we play with a line of four in defence because this suits the way we play on most occasions.
"We were talking last season about the draws we had at home and when teams play really deep against you, you need quality in the full back and central defensive positions.
"When we talk about Daniel Agger scoring goals and using the ball well it is because we know that these qualities are necessary if you want to turn the draws into wins."