Libyan club Al Nasr is studying the situation surrounding a temporary ban handed to team captain Khaled Magdy over suspicion of failing a test for a banned substance.
BBC Sport understands that the Confederation of African Football (Caf) has suspended the 24-year-old while they further investigate a positive test for a banned stimulant.
The suspension meant Magdy, who is also a Libya international, missed his side's 5-0 thrashing at the hands of Morocco's Hassania Agadir on Sunday in the first leg of the Confederation Cup quarter-final.
"The player is a pillar in our team and what has happened has shocked us," a member of the club's administration, who preferred to remain anonymous, told BBC Sport.
"We are still studying the situation and will not provide other details in order to protect the progress of work."
Magdy is yet to comment publicly on his temporary suspension.