Chelsea are chasing Borussia Dortmund striker Pierre Emerick Aubameyang.
The Daily Star says French sources state talks are underway between the two clubs over a deal for the Gabon international.
Jose Mourinho is close to completing a deal for £32m Atletico Madrid man Diego Costa, and he also wants Aubameyang at Stamford Bridge as competition for the Spanish striker as Chelsea look to bounce back from their barren 2013-14 season.
Aubameyang started his career with Italian giants AC Milan before spending time on loan at Dijon, Lille, Monaco and Saint Etienne.
