The French defender has returned to training with his teammates after spending six months on the sidelines with a cruciate knee ligament injury.
The former Monaco player impressed City fans in the early stages of the campaign following a £49.1m move to the Etihad last summer, but Guardiola has warned against rushing him back into the squad too early.
"The most important thing after six months is to be careful," Guardiola told reporters.
"He believes, 'I am strong, I will come back soon, I will play like I did before the injury'. That is not happening. Even if he believes he is strong, he is not strong enough. After six months, he has to be careful.
"But, of course, it's so important he comes back. He trains in all the training sessions with us. The knee is going well because he was operated on by the best doctor in the world (Ramon Cugat) for doing that. It's going really well. We are so happy because maybe he can help us for 20 minutes, 25 minutes."