Chelsea have asked Juventus about a price for Mattia Caldara.
While they're in advanced talks with Juve for Daniele Rugani and Gonzalo Higuain, Chelsea have also made an offer for Caldara.
Sky Italia says Chelsea have offered €30m for the young defender this week, but it has been bettered by Borussia Dortmund.
The Germans have offered €35m plus a further €5m in bonuses.
Caldara, a senior Italy international, spent last season on-loan with Atalanta.