After losing out on Everton defender John Stones, Chelsea are continuing in pursuit for another defender.
According to The Metro, the Blues are now considering a deal for Marseille defender Nicolas N’Koulou.
Jose Mourinho is believed to remain desperate to sign a defender, as they have experienced a slow start to their 2015-16 season.
Chelsea have allowed nine goals in their first four matches, including three in its loss to title rivals Manchester City.
The Blues have notched up just one win in their opening three games, taking maximum points in a 3-2 victory over West Bromwich Albion.
The Cameroon international is also being pursued by Norwich City, who have offered Marseille £14.5m.
The 25-year-old defender is believed to be drawing interest from Arsenal and Sevilla.
Chelsea have not made a formal bid yet, but it seems Mourinho is keen to make a move for the highly-rated Ligue 1 star.