The 20-year-old, who scored 20 goals for Feyenoord last season, is widely regarded as one of the best young strikers in Europe.
"There are 15 clubs who have enquired about the options for John. Right now there are negotiations with City. It's up to them, but I believe everything will work out in the end," Per Jonsson told Sportbladet.
City will reportedly sanction another season-long loan deal.