Chelsea midfielder Essien, who has recovered from a hamstring injury, only joined his team-mates on Wednesday after bad weather delayed his arrival in Angola.
"Essien joined us yesterday so we will assess his form in today's training to see if he will play tomorrow," Rajevac told a news conference.
Essien's absence would be a blow for Ghana, who have in their squad eight youngsters who won the Under-20 World Cup in Egypt in October.
"We have a very young team and we are going to play an experienced team," said Rajevac.
"It will be a young side out to prove themselves against Ivory Coast. It is going to be a very difficult game for us tomorrow but I promise we are going to beat Ivory Coast."
The 19-year-old Emmanuel Agyemang-Badu, part of the Under-20 triumph, was not afraid by the prospect of possibly having to deputise for Essien.
"I don't think there is pressure on us (the youngsters). We won the World Cup for Ghana so there is no pressure," he said.
"We have players like Michael Essien, they will show us how to get confidence. Maybe I will have the opportunity to play but no matter how hard I want it, it depends on the coach."
Ghana have yet to play a game after their opening match against Togo was cancelled following their departure from Angola after the deadly attack on their team bus.
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