Ghana captain Asamoah Gyan limped off training on Tuesday at the Accra Sports Stadium.
The Al Ain striker watched the rest of the session on the sidelines as he felt pains in his right thigh.
“I had a muscle sprain,” the 27-year-old told the media. “I'm still praying to God. I don't know what the problem is.”
The Black Stars team doctors are to recommend a scan to ascertain the exact cause of the pain as the four-time African champions prepare for a crucial 2014 World Cup qualifier against Zambia on Friday.
Gyan is, however, optimistic the game will end in Ghana’s favour.
“We’ve been talking about this game for quite a long time and we'll make everybody happy,” he assured.
Coach Kwesi Appiah said Gyan will be observed for a while and the scan report will determine his fate on Friday.