The Egypt coach has been shortlisted by the Nigerian Football Federation as a candidate to take charge of the Super Eagles in the 2010 World Cup.
Even though the Egyptian FA reluctantly agreed to let Shehata go, chairman Samir Zaher has set a deadline date for the Nigerians.
"The Nigerian FF has yet to make an official bid for Shehata," Zaher told Egyptian radio.
"We gave them until Friday to make their bid and start negotiating terms of a contract. After that, the matter will not be negotiable.
"Personally, I am against this move, but I had to allow it after the recent FA board's meeting."
Zaher is expected to approach his Nigerian counterpart Sani Lulu to open talks over the potential bid.
Shehata, who led Egypt to three successive Nations Cup titles, insists to have his current staff with him in case he took the Nigeria hot seat.