Sevilla president Jose Maria del Nido has revealed they've rejected a bid for Geoffrey Kondogbia.
Chelsea are among clubs keen on the French youngster.
"The bid wasn't sufficient," del Nido revealed.
"The idea is that he continues growing here at Seville, just like he did last season."
The transfer is complicated by third party matters, but that is understood not to have deterred Jose Mourinho who saw the young midfielder star in La Liga while coach of Real Madrid.
"There exists an obligation that if a formal, written offer of over six million Euros arrives then we must accept it and sell him, or match it and keep half of his economic rights," added del Nido.
"But they haven't done it in writing, which they must do."