The Brazilian's absence was notable in Monday's 1-0 defeat by title rivals Chelsea and his replacement Martin Demichelis was overpowered as City lost the midfield battle at the Etihad.
Concerns were raised that Fernandino could face a month on the sidelines with a thigh injury, but he is recovering well and has an outside chance of playing against Barcelona in the Champions League on February 18.
Fernandinho tweeted: "Good afternoon, I would like to tell you about my injury and quell rumors. I return to play in 15 days or less!"
The return of the midfielder would ease City's current injury problems as Sergio Aguero and Samir Nasri have also been sidelined at a crucial stage of the season.
Manuel Pellegrini's men remain two points adrift of Premier League leaders Arsenal and face Norwich and Sunderland in the League, and then an FA Cup match against Chelsea before Barca visit Manchester.