Bale has been out for a month since suffering a calf injury in the Champions League win over Borussia Dortmund, in which he scored a stunning volley, and he missed Wales' crucial World Cup qualifiers earlier this month, as they missed out on a ticket to Russia.
Carvajal has been on the sidelines for even longer after the right-back was diagnosed with a viral infection that was affecting his pericardium, the membrane enclosing the heart, in September.
While both players are on the comeback trail, neither will be fit enough to face Fuenlabrada in the Copa Del Rey on Thursday.
"Dani is doing well," Zidane told reporters on Wednesday. "He's undergone tests and they're positive.
"Today he's started to ride a bike and now his recovery will take time, but he's healthy and I'm happy about that. He'll have to go through the recovery process so let's see.
"Bale is already on the field, almost ready to train with the team, but I can't give you a date for when he'll be back."
Madrid travel to Wembley to play Spurs on November 1 in a match likely to decide which of the unbeaten teams claims top spot in Group H.
Former Barcelona boss Pep Guardiola has extensively spoken out on the issue, but Zidane would not be drawn into a political discussion.
"We are just going to play a game of football," Zidane said. "We are going to have security there, as always. We just think about preparing for the game, not about what can happen outside.
"Other coaches can talk about whatever they wish to. He [Guardiola] sees the chance to speak. But here [with the media] I just like to talk about football."