How to make default block for PR w/o release strategy

Hi gurus,

I am using item-wise release strategy with classification for purchase requisition. When assigned values for characteristics are satisfied system propose release procedure. But if not system do not create release strategy and show message Purchase requisition & cannot be released. This PR I can convert into PO w/o previously release. Could be this PR automatically blocked somehow and conversion into PO prevented?

Regards,

Harry