"That's good news," said Zidane, looking forward to Tuesday's Champions League game.
"We're all pleased he's with us and we'll see how we use him tomorrow," Zidane said, speaking from Borussia Park. "The important thing is that he's back and that's a big positive for us."
Hazard's last appearance came in the Champions League round-of-16 second-leg loss at Manchester City on August 7 at the end of a first season in Madrid undermined by ankle injuries.
The 29-year-old Belgian went off in the 83rd minute in Manchester and has not played since, victim of a muscular injury to his right thigh.
Real lost their Champions League opener 3-2 at home to Shakhtar Donetsk last Wednesday. They bounced back with a 3-1 Liga victory at Barcelona on Saturday.
"We want to perform as we did in El Clasico and take the points," said Zidane. "The performance we delivered in El Clasico is exactly the kind of display we need to produce tomorrow (Tuesday). We played well, fought as a team and the most important thing is that we try and do that tomorrow."
German midfielder Toni Kroos said Real cannot afford to start the Champions League group stage with losses.
"We know how important this match is after the defeat against Donetsk," Kroos told the press conference. "We already have pressure on us. This match is nothing but a final."
"We have to change this situation," Kroos said. "There are only six games in the group."