The 27-year-old damaged tendons during Real's 2-1 Champions League victory at Sporting Lisbon in November and underwent surgery in London.
"I hope he will be back before then (March 7)," Zidane told a news conference on Friday.
"He has been working well. He is enthusiastic and the only thing left is for him to train with the rest of the team, which is the most important thing."
Bale scored seven goals and set up three more in 16 appearances in all competitions for Real before getting injured.
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He is the only Real player currently out and will miss the first leg of their Champions League clash against Napoli on Feb. 15.
Real, who are one point clear of Barcelona at the top of La Liga, with two games in hand, play at Osasuna on Saturday, two weeks after their last encounter, a 3-0 triumph over Real Sociedad.
Their league match at Celta Vigo was postponed last week after bad weather in Galicia caused damage to the Balaidos stadium.
"We always want to play so 15 days without playing is a lot," Zidane said. "I don't know if it will affect us. We shall see tomorrow. We have trained well, we are physically well."
Second place Barcelona took advantage of Real's postponement by beating Athletic Bilbao 3-0.
Zidane is attempting to steer the club to its first La Liga crown since the 2011-12 campaign.
Osasuna have just one victory from 21 games and are rooted to the foot of the standings.
(Reporting by Adriana Garcia; Editing by Toby Davis)
