The Senegal international will have a medical but is unlikely to play against Blackpool at the weekend, even if the move is finalised.
"As far as I am aware, everything is agreed with St Etienne for him to come on loan for the season," said Jewell of a player who was on loan at Birmingham last season.
"He is having the medical this afternoon (Thursday). That doesn't mean he is signing, but we are very, very hopeful.
"Hopefully, by this time tomorrow, everything will be done and dusted. Even if it is, I don't think he will be available for Saturday."