Merreikh are seeking to land the Egypt goalie on a year-long loan after his relationship with Zamalek reached a dead end.
"The Sudanese club are yet to fulfill our requirements," Zamalek chairman Galal Ibrahim said in a television interview on Sunday.
"We told them Al-Hadari would leave on loan if they pay us $1 million but they could only table a $500,000 offer."
Al-Hadari is desperately aiming to leave Zamalek in the January transfer window, few months after joining them from Ismaili in the close season.
He incurred the Cairo club's wrath after skipping training before declining to attend a hearing on Thursday.
A dispute erupted after Zamalek's goalkeeping coach Emad Al-Mandouh accused the 37-year-old of insulting the club last month.
Mediator
Merreikh contacted former Zamalek board member Ahmed Refaat to act as a mediator in the negotiations.
"The club's football director Adel Abou-Greisha asked me to intervene to make things easier for them," Refaat, who was sacked by Zamalek in October after making inappropriate comments about wing-back Hazem Emam, told FilGoal.com.
"I have a good relationship with Merreikh, whom I managed and led them to the Sudanese league title in the 2005-2006 season.
"Al-Hadari has a strained relationship with Zamalek and Merreikh want him, so I believe a loan deal would be a good solution.
"It will financially benefit Zamalek and will give Al-Hadari the chance to play on a regular basis."
Al-Hadari is serving a four-month ban imposed on him by world governing body FIFA for violating his contract with Zamalek's arch rivals Ahli to join Swiss side Sion in February 2008.
The suspension should end in February.