Roma have been given until Friday to sign French midfielder Alou Diarra from Lens.
The Italians have already reached a é¼5 million (£3.4 million) agreement with the Ligue 1 outfit to sign the player on a four-year deal.
But the final negotiations have failed because the Stadio Olimpico side have prioritised their talks with Internazionale for David Pizarro.
The World Cup finalist's agent Janos Toth has now issued an ultimatum to the Serie A side and has given Roma one more day to decide the matter.
"We knew about the possibility of Pizarro, so we are not surprised," Toth told Corriere dello Sport.
"But we will wait for another 24 hours and then Diarra will consider the offers he has received."
Should the move fall through Marseille and Lyon are thought to be waiting in the wings to pounce.
If the Stade Gerland's star Mahamadou Diarra insists on leaving to join Real Madrid then Alou could well prove the ideal replacement.