The Blues sealed the arrival of the £27m Spaniard earlier this week after taking advantage of Arsenal’s reluctance to re-sign their former captain.
And now it seems Jose Mourinho’s midfield overhaul is still yet to be completed, with another Barca ace in the shape of Song on his radar.
Like Fabregas, the Cameroonian left Arsenal to join the Catalans and has also been deemed surplus to requirements.
Song’s spell at the Nou Camp has been less fruitful that the Blues newbie, with his playing time having been limited during his two year stint.
Talk of a return to the Premier League has been rife for some time, and a £10m offer from Chelsea is likely to be enough to convince the La Liga giants to let the 26-year-old head off.
Mourinho sees Song as an ideal upgrade on John Obi Mikel, who is set to be axed before the start of the 2014/15 campaign.
Liverpool, Arsenal and Manchester United have also been linked with the silky enforcer.