Crystal Palace must agree a deal with Trabzonspor before selling Alexander Sorloth to RB Leipzig.
Leipzig are among a number of clubs keen on the Norwegian striker.
But the Evening Standard says the Eagles must negotiate with Trabzonspor to end Sorloth's two-year loan deal before looking at another transfer.
The 24-year-old enjoyed a successful season in Turkey and Trabzonspor do have have an option to buy Sorloth for around £5.5million - if he plays 50 per cent of matches next season.