The 21-year old striker, who spent time on loan with St Mirren last season, was the subject of a phone call from the Hoops who are about to complete signing of Amido Balde from Rio's Portuguese rivals VitoriaGuimaraes.
"A few weeks ago I got a phone call from a person who was representing Celtic," he said.
"He told me that he was calling to ask the financial details of purchasing Esmael. He promised me to get back to me soon.
"Without any doubts, Esmael could be a good player for Celtic.
"He could be a good complement for Amido Balde up front. We are talking about two very powerful players.
"He did extremely well with St Mirren and I have been bombarded by calls regarding Esmael.
"But we want a straight sale. We're not considering loan deals."