The Nigeria midfielder left Getafe for Palace at the end of the summer transfer period, with his former club Cueta expecting a percentage of any sale.
Cueta president Luhay Hamido explained that the deal is an initial loan with the potential for a permanent transfer, contingent on specific conditions being met.
Cueta is due to receive 12.5% of the agreed €19m fee, as per Hamido's explanation.
Hamido stated that Uche's transfer fee has not yet been received and that he must play ten consecutive games as a starter for the purchase to be considered valid.
If Uche meets this condition, the loan agreement with the option to buy becomes mandatory, and Cueta would receive its percentage of the salary cap.
Hamido also mentioned that if Uche meets the conditions before the winter transfer window, Cueta may be able to use him again.