The Blues have been handed an injury boost ahead of the CL last 16 first leg clash, with the midfielder recovering from a knee concern earlier than expected.
The France 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 Tuesday.
The 26-year-old is unlikely to play a part against Sunderland on Wednesday, but Manuel Pellegrini feels he could be involved in Saturday's FA Cup clash with Chelsea, ahead of the visit of Barcelona on February 18.
"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," he told reporters. "We will see in the next few days, up until Saturday. I think there is a chance [Nasri could face Barcelona]."
The winger, who has four goals in 21 league appearances this season, took to Twitter to express personal joy at his speedy recovery, writing: "Happy to be back with the team, first full session can't wait to be back in the squad thank you for your support."