Agent Mino Raiola negotiated a €75m buyout clause in Haaland's deal for certain clubs, including Real Madrid.
However, Real's position is they won't make a hostile raid on BVB for Haaland as the two clubs enjoy a positive relationship. Reinier has just been placed by Real at Dortmund for a two-season loan.
If Real are to push through a deal for Haaland, they will seek to negotiate directly with BVB, rather than meet the player's clause.
Along with Haaland, BVB teammate Giovanni Reyna, 17, is also on Real's radar.