Barcelona have earmarked Chelsea and Arsenal target Nicolas N'Koulou as their main transfer priority for the forthcoming transfer window.
Since joining Marseille from Monaco in the summer of 2011, N'Koulou has become a permanent fixture in the first-team at the Stade Velodrome - he made 40 appearances in all competitions last term and has featured in all nine of his side's league matches this season.
The 22-year-old, who is a full international for Cameroon, is regarded as one of the best young defenders in Ligue 1.
He has been trailed by both Arsenal and Chelsea, as well as AC Milan and Roma, but Barcelona are thought to be best-placed to lure him away from Marseille.
However, his contract at the French club expires in 2015, so any club looking to secure his services will have to fork out at least £14.5m.