Brazil's Football Confederation (CBF) has vowed to exhaust all avenues to ensure Brazil-born striker Diego Costa does not switch allegiance to Spain.
CBF president Jose Maria Marin confirmed Saturday he has spoken to his Spanish federation (RFEF) counterpart Angel Maria Villar and warned that Brazil considered the 25-year-old their player, reports Xinhua.
"I had a friendly conversation with president Villar and made it clear that Felipe (Brazil coach Luiz Felipe Scolari) wants to select him (Costa) and that we think Spain's intention to call him up is illegal," Marin said.
"I also said that we are prepared to take every action possible to fight for the right of the CBF. He (Villar) responded by saying the decision lies with the player."
Costa has already been selected by Scolari to play in Brazil's friendlies against Honduras and Chile next month.
But the Atletico Madrid forward is yet to announce whether he will accept the call-up, having earlier this month told Spain coach Vicente del Bosque of his wish to represent La Roja.
World football's governing body FIFA is assessing a request by RFEF to sanction the player's nationality switch.
Costa, La Liga's leading scorer this season with 10 goals, has lived in Spain since 2007 and holds a Spanish passport.
He represented Brazil in two friendlies earlier this year but remains eligible to play for Spain as he is yet to play a competitive international fixture.
The Selecao will play Honduras in Miami Nov 16 followed by a clash against Chile in Toronto three days later.
