Chelsea defender David Luiz back at training as he bids to heal rift with Antonio Conte ‘that began in September’

David Luiz has returned to training at Chelsea but still faced an uncertain future at Stamford Bridge because of his strained relationship with Antonio Conte.

Luiz was left out of the squad that beat Manchester United on Sunday after questioning the tactics used by the Chelsea boss in the 3-0 loss at Roma last week.

The Brazil international also showed dissent when he was substituted in the first Champions League match with the Serie A club, at home in October.

But it is understood that the pair have not been seeing eye-to-eye since the first few weeks of the campaign.

A source told Standard Sport there was a problem between the two in September and there were fears at the time it could develop into another Diego Costa saga at Stamford Bridge.

Costa fell out with Conte after asking to leave the club three times, while also questioning his tactics and training methods.

The forward was told in January that he would be sold this summer but he completed a move to Atletico Madrid in September after going on strike during the summer in Brazil.

Chelsea maintain the situation between Luiz and Conte is not as serious as it was with Costa and the fall-out has occurred only recently.

Luiz, who Conte described last April as one of the best defenders in the world, was a key member of the club’s title-winning squad last term after rejoining the Blues from Paris Saint-Germain for £34million.

He has also played through the pain barrier this term, having suffered wrist and calf injuries.

​Luiz will be given an opportunity to return to the squad if he shows a commitment to fight for his place and the right attitude. Conte has already made it clear to all his players that he is not willing to accept anyone questioning his decisions and wants the squad to be united.

Luiz, 30, faces a challenge to get back into the side because of the impressive form of 21-year-old Dane Andreas Christensen.

When asked about Luiz having a future at Chelsea after Sunday’s game, Conte said: “I don’t know. He has to work really hard, otherwise he is on the bench or in the stands.

“I must take the best decision for the club, not for a single player. Christensen is the present and the future for Chelsea.”