Chelsea defender Toni Rudiger is in contact with Bayer Leverkusen midfielder Kai Havertz about a move to Stamford Bridge.
Havertz, rated at £90million, is the Blues' top remaining summer target after they landed £53m striker Timo Werner from RB Leipzig and Ajax wizard Hakim Ziyech for £37m.
Bild journalist Christian Falk claims "agent Rudi is on a new mission".
He added in a tweet: "True: @ToniRuediger is in contact with Havertz since a couple of weeks and tries to convince him."
The 21-year-old already has seven full caps, having also provided 17 goals and nine assists for fifth-placed Bundesliga side Leverkusen this season.
Rudiger has admitted he spoke with Werner before he agreed to join Chelsea last month.
