Spanish giants Valencia reportedly made a late move for the highly-rated defenders.
De Boer told Ajax TV: “Greg and Jan can see that there is something beautiful growing in Amsterdam.
“They have both always emphasised that they are really enjoying themselves and it is not necessary to have to leave now.
“And besides, we play in the Champions League.”
De Boer admits he feared the duo would leave after being told by technical manager Danny Blind that there were interest from abroad.
“I said, ‘I do not want you calling’,” he added. “There were rumours that Inter were in the market for them in January.
“If the club accepts the set amount in the contract, then there’s not much you can do.”
