Antonio Conte believes he can turn David Luiz into one of the best defenders in world football and has pointed to the transformation he oversaw in Giorgio Chiellini, Andrea Barzagli and Leonardo Bonucci at Juventus as evidence that his coaching methods work.

Chelsea secured David Luiz’s surprise return to Stamford Bridge on transfer deadline day, for an initial £34m from Paris Saint-Germain, having been knocked back in their attempts to secure centre-half reinforcements from Serie A. During the Brazilian’s first spell in south-west London the team won the FA Cup, Champions League and Europa League, yet the deal struck with PSG in 2014, which would potentially have been worth up to £50m, still appeared sound business given the defender’s rather erratic form.

Conte, however, praised the positive attitude the 29-year-old has already brought to the dressing-room since re-signing for the club and is set to start with David Luiz alongside John Terry at the heart of his defence at Swansea on Sunday, having trained with that combination this week. While there was a warning a lack of focus on the pitch will not be tolerated, the manager believes he can improve a defender who already boasts 55 caps for his country.

“At 29, he is at a fantastic age to become one of the best defenders in the world,” said Conte. “You can always improve and I’m seeing great commitment from him. He wants to play for Chelsea. This is a great opportunity for him also to improve. I repeat: he has good characteristics to become a fantastic defender.

“It’s important to remember when I started at Juventus, with Chiellini, Bonucci and Barzagli, the defence had been conceding a lot of goals. I remember that, before my arrival, many people told me: ‘They are no good, these defenders. No good.’ But then I started to work with them, I found a great commitment and attitude. Through the work, now we are talking about three of the best defenders in the world in Chiellini, Bonucci and Barzagli. But remember, when we started in that first year at Juventus, it wasn’t like that.”

While Chiellini was already well established at Juve, Bonucci had been at the club for only a year when Conte arrived as manager in 2011, having joined from Bari. Barzagli was secured from Wolfsburg the same summer. “I see David Luiz’s qualities in the middle, between [those of] Bonucci and Barzagli,” said Conte. “He has good technique and good personality, like Bonucci, and likes to play football. Also, I find a good potential physically, like Barzagli’s.

“I don’t like to speak about the past. Now I’m the coach of David Luiz. And, also, I have a great responsibility to improve him and these [defensive] aspects. If someone thinks that this player loses his concentration during the game, I won’t be happy but my task is to improve him in that aspect. I want to work with him. David is a mature player but, if he must improve in some aspects, I’m here for this reason.

“The only way to do that is through work. Not talk. You need to work with them on the training pitch every single day. You put your sweat into it. I put my sweat into [working with] my players. To improve them. To work on any weaknesses and make them stronger. We know that David can improve in defensive situations, but I’m very happy he is here.”

The arrivals of Marcos Alonso, who will compete at left-back, and David Luiz will increase competition across Chelsea’s defence in the weeks ahead, with Kurt Zouma also to be integrated once he returns from a knee injury. Branislav Ivanovic and Gary Cahill may find themselves under immediate pressure to retain their places. “But, in a great team, there must be competition,” said Conte. “We are Chelsea, a great team, and if a player plays in a great club, he knows there is a good competition for places. It’s important for me to see the right attitude always, and to see who deserves to play. I don’t see any problem about this here.

“I’ve only been working with David Luiz for six days, but my first impressions are he’s a positive guy. He’s always with a smile, and that’s good. He faces life the right way. It’s important, this. Then, when we start to work, we work. It’s important to have players with good personality in a squad, but I want that personality transposed on to the pitch. This changing room is a good changing room at Chelsea.”