Six of Chelsea's past 10 league goals have been provided by Hazard and it was the Belgian that unpicked West Brom for the opener in the 25th minute, with an assist from Olivier Giroud on his full debut.
However, the France worldwide was replaced by Alvaro Morata in the 61 minute of the game after receiving medical treatment on a couple of occasions following challenges with Ahmed Hegazi and Jonny Evans.
"It's important that they play games to find their best physical condition", Conte said.
Chelsea, meanwhile, were clinical in the box, and swept the Baggies aside with two goals from Eden Hazard and one from Victor Moses.
"(It) was the first time to play from the start with us.
"For sure, for me it's important". We missed a great chance and five minutes later we were 1-0 down.
"I think he played very well in the last 30 minutes with great personality, with great spirit". I couldn't feel better so I only have in mind the idea of training with my team and helping us achieve success.
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"We need him up and running as it's goals we've struggled with", manager Alan Pardew said after the match they lost to champions Chelsea.
Defender Andreas Christensen also makes his return from injury, and he will go straight into the line-up after missing a game and a half.
"We must be pleased for the Giroud performance", Conte said of the Frenchman, who was replaced by Morata on the hour after a battling display in which he had his head bandaged and took a blow to the ankle.
"Obviously we don't have too much time for the integration but I feel very good and the boys are very good to me".
Chelsea's recent slump and Conte's outspoken comments over his lack of input to the club's recruitment strategy had seen the odds slashed on him becoming the latest coach to be fired by Chelsea owner Roman Abramovich.
West Brom only had themselves to blame for not getting back into the game early in the second period. For our confidence it was very important to win and keep a clean sheet.