Chelsea have interest in Jonas Hector of Cologne, who is currently considered Antonio Conte's top transfer target.
Hector has established himself as first-choice left-back for Germany and played in every game for his country at Euro 2016 this summer.
Liverpool has also expressed interest in Hector.
Cesar Azpilicueta has been used as Chelsea's left-back for the last two seasons, but Conte could prefer a natural player in that position, especially if he decides to change formations and play 3-5-2 at Stamford Bridge.