The 32-year-old defender will have a final medical on Tuesday before completing his move to the Western region club, according to a club official, before joining his new teammates' conditioning camp starting Monday.
Najjarine replaces Anas Bani Yaseen, 25, the Jordan international who returned to Al Wahda after a one-year loan spell at Dhafra.
The only foreign player of last year's contingent to be retained is Makhete Diop, the Senegalese forward who topped the club's scoring charts last term with 22 goals in all competitions.
Dhafra finished a creditable eighth in the 14-team league with 36 points, the best haul in the history of the club top-flight participation.
Dhafra have signed the Ghanaian forward Emmanuel Clottey on a one-year loan from Esperance of Tunisia, leaving them with one available slot in their squad for a another overseas signing.
Khalifa Al Tunaiji, the club's chairman, said the club's objective was to strengthen their attack.
"We have made some good signings over the summer in consultation with the head coach and obviously want to build on our excellent performance, particularly in the second half of last season," he said at the time of introducing Clottey to the media.
Clottey, 25, is an international teammate of Asamoah Gyan, the Al Ain striker, who topped the domestic scoring charts the last two seasons. Clottey has replaced the Ivorian forward Amara Diane.
Dhafra have also strengthened their Emirati workforce after signing Ibrahim Saeed Masoud from Baniyas, Al Wasl's Ali Abbas and Kalba defender Ahmed Sulaiman.
However, they have lost Hazza Salem and Bandar Al Ahbabi, both of whom returned to Al Ain.
Meanwhile, the Brazilian striker Jair Eduardo Britto da Silva has moved to Emirates from the Japanese side JEF United Chiba on a one-year loan deal.
Jair, 25, said he has rejected several offers from other clubs to join UAE club after consulting with fellow countrymen Luiz Henrique and Careca about the Arabian Gulf League.
"They assured me that I will find great potential and all the support I need to succeed here," Jair said.
"I know that the level of football in the UAE has evolved rapidly and I hope to show my own playing style here and perform well in the league."
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