Can you tell us if he’s having any more leakage?
Such as after he drank?
Has he eaten today?
By dinnertime tonight you should see if he feels like a little something.
Soft foods though, remember? Nothing with chunks, or seeds.
Any chance you could post a photo today?
If it is indeed a puncture to his crop, and if indeed it is still draining, I would either suture the hole or close it with Crazy Glue as has already been suggested. Otherwise it may not heal and remain as a fistula.