The French international was set to be out for eight weeks with a knee injury suffered in a 2-0 win over Newcastle in early January, but better-than-expected progress saw him return to training on Tuesday.
Manuel Pellegrini: "Nasri and Javi Garcia started training [on Tuesday] with the squad, we will see in the rest of the week if they can be fit for Saturday.
"We will see in the next few days, up until Saturday. I think there is a chance [Nasri could face Barcelona]."