If one reads سبحان ربي العزيم  with a ز, this will invalidate the Salah; therefore, if he cannot pronounce سبحان ربي العظيم adequately, he may recite سبحان ربي الكريم until the time when he is able to pronounce العظيم سبحان ربي correctly and properly. (Shaami Vol. 1 Pg. 494) 

AND ALLAH TA'AALA ALONE IN HIS INFINITE KNOWLEDGE KNOWS BEST

ANSWERED BY: Sohel Lala 

CHECKED AND APPROVED BY: Mufti Muhammed Saeed Motara Saheb D.B. 

Islamic Date:2 Jumadal Ula 1440 

English Date: 9 January 2019