Chelsea manager Antonio Conte has explained what he expects from his three-man defence ahead of John Terry's potential return for the EFL Cup fourth round at West Ham. The Italian boss has also hailed the importance of the fans' support after they played a key role in the previous round's victory over Leicester City, when the Blues came from two goals down to win 4-2.

Conte made his mark at Juventus and the Italian national team with a 3-4-3 formation. However, the boss was forced to abandon that system for his first games at Chelsea after starting the campaign with just two fit centre-halves in John Terry and Gary Cahill.

The return of David Luiz from PSG in the last days of the transfer window looked a move to finally implement the three-man system at Stamford Bridge. However, his plans were hindered again after club captain John Terry suffered a strained ligament in his foot during the draw at Swansea on 11 September.

But consecutive Premier League defeats to Arsenal and Liverpool with a 4-3-3 encouraged Conte to switch to his preferred system at Hull, deploying versatile Cesar Azpilicueta alongside David Luiz and Gary Cahill in the three-man back line.

The decision has paid off as the Blues have since enjoyed three victories and three clean-sheets. Conte is expected to stick to the same formation for the visit to West Ham tonight (26 October), despite being ready to make a number of changes to his line-up.

On Tuesday (25 October), he suggested that Terry could start after sitting on the bench for the wins over Leicester and United. And he has now explained to his defenders what he wants from them in the 3-4-3 formation.

"The central defenders on the right and the left must be very fast and aggressive. The players that play in the middle of the three defenders must be more tactical, must reflect more and find the right position, and also call the line up and down," Conte explained to the Chelsea website. "In these last three games we did very well. It's normal when you play with the same players. They take confidence in the role to play together."

"It's important also for example in this game, the cup, to find a new solution. If you have [an injury] during the season, then it's important to have a good solution ready."

Meanwhile, Conte has also encouraged the Chelsea fans to maintain their vocal support at West Ham to help them to secure qualification for the quarter final of the EFL Cup.

"I always appreciate a lot the behaviour of our fans when we play away. In every single moment they are behind us. I remember when we were losing 2-0 at Leicester after 20 minutes, they were pushing us a lot," the boss said. "This is very important. I want them to stay behind us and to push the players, in every moment of the game, positive or negative, to win. Our fans, if they want, can be a 12th player."

"One reason you want to work in England is for the atmosphere that you breathe during the game. It's very special in this country. At every game you can see families coming to watch the game. The first thing is to come and celebrate football, to stay together and to live a fantastic moment with your family."