The 22-year-old is expected to join the Eredivisie champions on a five-year deal.
“The final decision has not yet been given,” Blind told De Telegraaf.
“But we have held discussions with Jasper and his management and there will be no problem.
“As it stands now, he will sign a five-year contract.
“We had an initial bid of €1.8m turned down but we have increased that by a good amount. It now depends purely on NEC.”