It is understood that Luiz suffered a broken wrist after colliding with the advertising boards during Sunday's Premier League clash with Arsenal at Stamford Bridge.
Suspension ruled the Brazilian out of Wednesday's EFL Cup fixture with Nottingham Forest, while the defender will be banned for Chelsea's next two Premier League games after picking up a late red card against Arsenal.
Conte, however, has claimed that Luiz will be fit to take on La Liga giants Atletico in the Spanish capital next week.
"He must be okay. David is an important player for us. For sure he will be ready for the game against Atletico Madrid," Conte told reporters.