Professional football player with scaphoid fracture. can i play before it completely heals?

Better to wait: Of course you could play before it heals but that would not be best for your body. If you reinjure the area this could have further consequence creating more damage, perhaps permanent.

Depends on position: Needs to be casted at least for 6-8 weeks, depending on location may have a increased chance of not healing or avascular necrosis. Some professional line men 9offensive play with cast since they are not supposed to grab with their handstand just block. Check with tea doc.