Overmars is prepared to sell De Jong to Barca this month, reports Sport, but everything will depend on their Champions League qualifiers.
If Ajax fail to qualify for the group stage this month, they will sell De Jong to Barca. A final qualifier will be held on August 30.
Barca would prefer to do business immediately, but have accepted Overmars' terms.
The Catalans are prepared to pay €50m to sign De Jong should he become available before the European transfer deadline falls.