Most definitely get it seen by a doctor - he will probably need a course or two of antibiotics, they may need to do an ultrasound to check whether there is any infection behind the wound. Please this needs to be taken seriously, even a small bacterial infection site can bring a healthy grown man down...he does NOT want to spend several months getting the wound cleaned and packed every day, which is a possibility if it comes on. Healthy tissue *can* die. The green colour in particular is a worry. Wound care is really important.