Osasuna are also claiming that Blues have offered to sell the player to them if they match the fee they paid for the player.
A statement on the Osasuna website said: "Osasuna have received a document from Birmingham City in which they have communicated that they do not wish to have any conflict with Fifa, nor with Osasuna.
"It offers Osasuna the possibility of paying £2.5m, which the English club confirm having paid for the player, and giving up the transfer of the player to Osasuna." 