Luiz was a surprise omission from the Blues squad for the visit of Jose Mourinho's side, with Denmark global Andreas Christensen named from the start of the 1-0 victory at Stamford Bridge.
"The coach has to make the best decision for the team and the best decision for the team was to play with Christensen", Conte said. It's normal. I have to make the best decision for the club, not for a single player.
When questioned specifically on the case of David Luiz, he said: "It's only a tactical decision".
"It's normal, this can happen to everyone of my players".
According to media reports in Italy, former Juventus and Azzurri boss Conte has emerged as a possible replacement for Montella, who has overseen five defeats in 12 Serie A matches this season.
"I have to make important decisions". He's a great player so it's normal for me [that he's done so well at United]. "Sometimes I can do the best things for my team".
"Christensen came in yesterday and played very, very well indeed in a massive game".
Perhaps that is why, as the Mirror put it, "David Luiz was left upset as he was made to watch from the side of the pitch and act as a ball boy".
"It is a big call because if you take on these players in that dressing room, where David Luiz is a big influence, a big character, you can lose at this club". I was very happy for this.
Wilkins, who also represented Manchester United during his playing career, believes Luiz would be better employed as a midfielder but feels he is too much of a liability at the back.
The decision led to talks of unrest between the Italian manager and Luiz, but the tactician has moved to rubbish the claims.