The 20-year-old is one of a number of South American starlets being linked with a summer move to Europe.
Premier League eyes are said to have fallen on the tricky playmaker, with Tottenham Hotspur credited with holding an interest as they pursue creative additions.
Borussia Dortmund and Porto are also reported to be keen on a man who has been capped three times by Brazil.
Atletico are, however, adamant that no formal bids have been put to them.
They have also made it clear that it would take around £21million to lure them into a sale.
Kalil said: "Bernard will only leave for 25million euros.
"We have great relations with Porto and their director Antero Henrique, but no offers for him have been made as yet."