Agent Mino Raiola is the main stumbling block in Barcelona's pursuit of Matthijs de Ligt, according to Mundo Deportivo.
The highly-rated Ajax youngster is wanted by the Catalan giants, who last month announced De Ligt's team-mate Frenkie de Jong would be joining them in the summer.
However, Raiola will demand over £8m in commission in any deal involving De Ligt.