The Wales international was forced out of the starting XI for Real's 4-1 win over Getafe on Sunday with a thigh injury, and had looked a doubt for the derby on Saturday.
However, head coach Carlo Ancelotti has confirmed that the 24-year-old should play a part against Diego Simeone's side at the Santiago Bernabeu.
"Today he trained apart from the rest of the squad and I think he will be ready for Saturday no problem," Ancelotti said.
"He won't be available tomorrow but we have time to train with him to prepare him well for Saturday.
"He was a bit sad after the (Getafe) game but he changed quickly because he started to think about Saturday's match."
Ancelotti also believes the club made the right decision in not risking Bale on Sunday.
"It's not a muscle injury because if that were the case he would not have been able to train yesterday and today and he wouldn't be available for Saturday," he added.
"I don't know exactly what happened but the best thing is that we didn't take the risk of playing him (against Getafe) so that he can be available on Saturday."
Bale will miss Wednesday's La Liga trip to Elche but Ancelotti will be pleased to welcome back the Welshman for what he feels will be a difficult game on Saturday.
"Atletico Madrid are the team that have surprised me the most. They are playing well," he added.
Real have dropped just two points in the league this season - in a 2-2 draw against Villarreal - but Ancelotti feels his side have room for improvement.
"My team is improving, I'm happy with the work being done, I see a team that wants to improve in training, they are professionals," he continued.
"We have played good matches, not with a lot of consistency though and that's what needs to be improved.
"We have to be careful in this match (against Elche), we already have the experience against Villareal and it was very difficult.
"Tomorrow will be the same, a team with great enthusiasm and playing against Real Madrid is a great motivation for them."
