When is the right time to re-exercise (soccer) after open laminectomy surgery? or what's the sign that shows that i am ready to play? (i'm male 29yrs)

Why not : Pose this question to your surgeon. As he/she will best be able to guide your through your rehab due to his/her familiarity with your anatomy and the particulars of your surgery.

Full healing: Since this can vary from one to another, have your surgeon let you know when your back is stable. But you might even do better using physical therapy with a gradually escalating exercise program.