Arsenal forward Pierre-Emerick Aubameyang missed his Gabon side's draw against Ghana in the Africa Cup of Nations on Friday night after a serious of scans revealed heart lesions.
Aubameyang has recently recovered from COVID-19 after testing positive for the virus when arriving in Cameroon last week.
Arsenal's doctors have reportedly been in contact with the Gabon medical team and the situation is believed to not be serious, with the striker feeling well.
His teammates Axel Meye and Mario Lemina were also diagnosed with the same issue and were also left out of the squad, although the Gabon Football Federation have suggested that omitting all three players was a precaution.
"Medical examinations show cardiac lesions and CAF did not want to take any risks," the Gabon Football Federation wrote on Twitter.
Gabon head coach Patrice Neveu played down fears over the scan results, saying they were merely a "small problem" and that he decided to not play the trio to not take any unnecessary risks with their health.
Gabon need just a point from their final group match against leaders Morocco on Tuesday if they are to qualify for the last 16 of the competition, but it is still unclear if they will have Aubameyang, Meye and Lemina available.