Michael Essien's conduct prior to Ghana's final group match against Portugal at the World Cup is under review.

The midfielder, who was named as a substitute for the Group G game in Brasilia did not join the team in the pre-game warm-up.

According to Black Stars coach Kwesi Appiah, he has furnished the management about Essien's conduct, which was brought to his notice by a member of his technical staff.

"I was notified by my technical team that he [Essien] did not warm up though he was supposed to," Appiah said on Wednesday at a press conference in Accra.

"That was some minutes before kick off against Portugal.

"Due to the urgency of the game, we had to carry on and after that I reported his conduct to the GFA in my report for the necessary action to be taken."