Sule is highly rated in Germany and he could prove to be a superb long term investment for the Blues.
The 25-year-old centre back has started just eight league games for Bayern Munich so far this season and he needs to play more regularly in order to continue his development and fulfil his world-class potential.
It remains to be seen whether Chelsea can lure him to Stamford Bridge with the assurance of regular game time.
Bayern are thought to be keen on Upamecano and his arrival could push Sule further down the pecking order.
The Blues are in desperate need of centre banks and they will have to upgrade on the likes of Cesar Azpilicueta and Antonio Rudiger at the end of the season.
The Spaniard is in the twilight of his career right now and Rudiger has been quite inconsistent since his move to Chelsea.
Sule could be the ideal partner for Thiago Silva at the back for the Blues and it remains to be seen if the Premier League club can convince the German champions to part with the 25-year-old at the end of this season.
According to journalist Christian Falk, the Blues are keeping tabs on David Alaba and Dayo Upamecano as well.
Alaba is expected to leave as a free agent at the end of this season and Upamecano has been linked with several European clubs.
It will be interesting to see who they end up signing eventually.