Hurt my hamstring last thursday when can I come back ?

What is the 'hurt?' 'hurt' can be anything from a direct hit causing a contusion or bruise, to a strain of the muscle, to a tendon injury (connects muscle to bone). And any of these can be mild, moderate, severe, or even a complete muscle rupture. Need a sports medicine/orthopedist to diagnose, to get specific DX and management. In general with musculoskeletal injuries, pain means back off and check it out.
Suggestions. Hs strains can be tricky to overcome. To keep your overall fitness during recovery then consider upper body/ core circuit training (include ube). Depending on your stage of recovery you also may be able to walk, swim, bike (low resistance). In relation to your lower body gradually return to activit... Control pain, regain motion/ strength/ and endurance over time. (drmarkgalland.Com - 12/26/12).