Borussia Dortmund have turned down Chelsea's opening offer for striker Erling Haaland, according to Sky in Germany.
Chelsea offered Dortmund either Tammy Abraham or Callum Hudson-Odoi in part exchange for Haaland, but the Bundesliga side are determined to hold onto the 20-year-old.
The club are keen to sign a new striker this summer after struggling in front of goal at times last season.
Despite winning the Champions League, Thomas Tuchel's side lacked a reliable presence in the penalty area, with Timo Werner and Abraham's 12 goals each making them the club's joint top scorers.