Chelsea have reportedly already tabled an offer for Bayern Munich defender Niklas Sule.
With Dayot Upamecano set to arrive at the Allianz Arena in the summer from RB Leipzig, Sule's future with the Bundesliga and world champions remains shrouded in uncertainty.
Bayern chief Karl-Heinz Rummenigge has already admitted that a new deal for the defender - who is out of contract in 2022 - may not be possible unless certain conditions are met.
Now, German outlet Abendzeitung reports that Chelsea - who are expected to be in the market for defensive reinforcements this summer - have now made an offer for the Germany international, and a sale in the upcoming transfer window cannot be ruled out.
The report adds that the imminent arrival of Omar Richards from Reading will see Lucas Hernandez deployed centrally alongside Upamecano - a move which will push Sule further down the pecking order - and Thomas Tuchel is keen to take advantage by bringing the 25-year-old to the English capital.
Sule - also capable of filling in at right-back - has struggled for consistent starts with Bayern this term, featuring from the first whistle on 12 occasions in the 2020-21 Bundesliga campaign.