The 19-year-old has emerged as one of the best young players of his kind in world football after playing 34 times in Serie A for Bologna last term.
His form has prompted a Europe-wide chase for his signature with the two Premier League title challengers credited with a strong interest in the midfielder.
However, his agent Daniele Piraino has revealed that it is Aston Villa – relegated to the Championship last term – who have made the formal offer for him.
Villa boss Roberto Di Matteo has a deep knowledge of Italian football and believes he may be able to land the Guinean with a £14.7million fee reported.
Piraino told Sport Italia: “It’s true that there’s an offer from Aston Villa, but it continues to be in Bologna’s hands, I have no say”.