Earlier this month, Guardiola confirmed that Sane was still “weeks” away from full fitness.
While his body may be recovered from the ACL injury, Sane needed to build up his match fitness through rigorous training.
“He’s started training with us,” Guardiola said, ahead of City’s 2-0 win over West Ham United.
“When you have an injury, especially like this one for six months, you need to recover the tempo, the rhythm, the confidence in your body, in your knee; don’t think about the injury.
“It needs time. It’s not like an ankle, for example, or a muscular injury.
“The injury to the knee always needs time. He needs weeks.