Antonio Conte faced the task of justifying David Luiz's omission from the team ahead of Chelsea's Premier League fixture against Manchester United on Sunday afternoon.

The Brazilian's absence for one of the Blues' biggest games of the season was a shock to home supporters, with the 30-year-old having formed a vital part of Chelsea's defence.

Conte instead opted for 21-year-old Andreas Christensen, while Luiz was left to watch on from the stands after also failing to make the bench, behind Antonio Rudiger and Ethan Ampadu.

Chelsea's midweek 3-0 humbling at the hands of AS Roma in the Champions League again highlighted the Blues' defensive troubles  - having already conceded 10 league goals this campaign, also.

The Italian had no choice but to react to their poor display in Europe, but few would have expected Conte to axe his experienced Brazil international who sensationally returned to the club last year.

Luiz's complete omission a shock

The selection of Rudiger over Luiz would have been understandable, but his complete omission against United and selection of a youthful, less experienced player was a shock.

It was certainly a decision that could land Conte in hot water if they lost at the hands of former Blues boss, Jose Mourinho.

Pre-match, speculation grew of a fall-out between Conte and Luiz. However, the Italian quashed the rumours with a verdict that could be rather damning for the Blues defender.

"(Leaving David Luiz out) is a tactical decision," said Conte, per the Daily Mail. "There is Andreas Christensen in good form and we have Ethan Ampadu who is a good, young player at the club.

Conte hints at reason for Luiz's absence

However, Conte also added a comment that somewhat appeared to question Luiz defensively.

"We are conceding many goals so you have to find stability and solidity," Conte added. "We have to be patient with the team and defend in the right way."

The Italian's decision is still somewhat baffling, given Luiz is one of Chelsea's key senior figures. But time will undoubtedly reveal whether there is a deaper lying issue.