Chelsea boss Thomas Tuchel is determined to bring in a new centre-half this summer.
Tuchel has considered a move for Bayern Munich defender Niklas Sule, though the Germany international isn't his only option, reports Goal.
Sevilla's France international Jules Kounde is also on Tuchel's shortlist.
Watching developments is Real Madrid president Florentino Perez, who could compete with Chelsea for Kounde if he loses Raphael Varane to Manchester United in the coming days.
Both Kounde and Sule are available this summer - if Chelsea are willing to pay the right price."