A statement was released by the Giallorossi earlier this week announcing that a preliminary agreement had been reached with the Sheikh for an investment into the club.
An investment of up to €100m has been reported, though Unicredit, who still part-own Roma, have claimed that the Sheikh must prove he has the cash by next Monday or Tuesday.
"By Monday or at most Tuesday, the Sheikh must prove he has the cash to invest," said Unicredit vice-director general Paolo Fiorentina.
"Without money, it will all disappear. Perhaps this move will have to be dragged out for a little longer.
"We might be wrong, but we do have some doubts on the consistency of his funds."
On the pitch, Roma secured three vital points in Serie A, beating Atalanta 3-2 on Sunday afternoon.