Liverpool have been heavily linked with a move for the 21-year-old and fresh speculation has suggested that Borussia Dortmund have made contact to enquire about his availability.
De Boer is realistic about the chances of Eriksen staying in Amsterdam as he knows there is bound to be a lot of attention when the transfer window reopens.
"If clubs do not show up, then they don't have any intelligence," De Boer told reporters.
De Boer admitted that Eriksen would be a perfect fit for the Bundesliga but did not confirm that he had been approached by Dortmund boss Jurgen Klopp.
He said: "If I was called than I wouldn't tell it to you. But Chris would suit well in Germany."
Ajax director of football Marc Overmars added in De Telegraaf: "Informally a number of clubs have contacted us."