The Premier League duo are both understood to be monitoring the progress of the 20-year-old, who has been dubbed “the Nigerian Ronaldo” because of his pace and trickery.
Scouts are understood to have seen the Gent forward when casting an eye over his team-mate Laurent Depoitre – another forward interesting both English clubs.
Simon caught the eye and The Daily Mail claim both Spurs and Liverpool wanted to sign him when he was a teenager.
He opted to train with Ajax instead before heading to Slovakia to sign for AS Trencin where he impressed and earned his move to Gent.
They are understood to be desperate to keep him but reports in Nigerian newspaper HLNclaim general manager Michel Louwagie is willing to business at £15 million.
Although the initial move cost Gent less than £1m just over 12 months ago, they feel they can get top price for the man who helped them finish as runners-up in the Belgian Pro League last season.