The forward fractured his right ankle while on Belgium duty in June, but was used by his country in World Cup qualifiers against Gibraltar and Greece during the recent international break.
Conte was initially baffled by his call up before admitting his minutes for Belgium may be of benefit to the Premier League champions.
And the Italian is now pondering how best to use Hazard for the first time this season at the King Power Stadium on Saturday.
"I spoke with Roberto [Martinez, Belgium manager] and we tried the right way to improve his fitness. I was very happy for him to play against Gibraltar and 30 minutes against Greece. I totally agreed with him," Conte told a pre-match news conference.
"Now he is available, he is in the list for the squad. He is improving a lot, he is working very strong to be ready.
"Now I can count on him. I have to decide the right minutes, but he is available now.
"When there is a bad injury and surgery, it is normal to pay attention to his recovery. Don't forget he is an important player for us, to play soon."
Chelsea landed midfielder Danny Drinkwater in a deadline day deal from Leicester but, although he is in the squad, Conte is unsure whether he will play against his former employers.
"Danny, we are working with him and trying to make him in the best physical condition. It is normal when the transfer window closes, when you go into another team it's not simple," he added.
"He is a good buy for us, he has improved his condition and in the squad for the Leicester game but I don't know when he is ready to play."
Conte added that Davide Zappacosta, another deadline-day signing from Torino, can quickly get up to speed with his methods.
"He played against Israel [for Italy], which shows he is in good condition. I worked with him and he knows my style of football. For him it is more simple for him to adapt our style," he said.