Henry Onyekuru left Galatasaray's training session on Wednesday with pain in his left lower back muscle as the Lions prepare for Sunday's derby against Besiktas in the Turkish Super Lig.
The Super Eagles forward was withdrawn as a precautionary measure, and he is expected to undergo further medical examinations on Thursday to determine his health condition.
Onyekuru has been in fine form for Galatasaray since his return to the Turk Telekom Stadium on loan in January, after struggling for playing time at Monaco.
The 22-year-old has inspired the Lions' charge for the Turkish Super Lig title with his attacking prowess, and he has played six league matches so far with a goal and an assist to his name.