Chelsea are interested in signing Argentine defender Valentin Barco, 21, from sister club Strasbourg.

Chelsea are actively working to sign Joaquin Panichelli from Ligue 1 side Strasbourg, but AC Milan have also shown interest in the 23-year-old Argentine striker.

Strasbourg full-back Guela Doue, 23, has been watched by Premier League clubs Chelsea, Aston Villa, Brighton and Brentford - though the French side might demand a transfer fee in excess of £26m for the Ivory Coast defender.

Sunderland have agreed a club-record £30m fee with Strasbourg for 21-year-old Senegal midfielder Habib Diarra.

Crystal Palace are chasing Chelsea-linked Strasbourg striker Emanuel Emegha - in case Jean-Philippe Mateta is sold.