hi, as you mentioned about the anteriolisthesis and the disc degenerative disease at L5 - S1 . First we need to see if he has any symptoms. Usually, MRI scan has to be correlated with the Clinical symptoms. Also, you can take him to physical therapy, for learning the exercises which will help stabilize the spine. Also, this exercises he need to follow in future to avoid recurrent back aches. exercises like - core stability, spine Strengthening, pelvic floor Strengthening etc. Based on the weakness of the muscles the exercises will be guides. Also the anteriolisthesis has to be controlled because the listhesis has only one direction - that is progression. Usually performing regular exercises will help to keep the muscles intact and stabilize the listhesis. Also if ignore now may lead to recurrent back aches which may not allow him to perform well. Also contact sports has to be avoided for time being. Since he plays football - the mobility of the spine is high and also the weight applied on the L5 - S1 level. Once the muscle is strong the load of the stress will be borne by muscles or else the joints. For more details you can ask me directly I will be happy to help you. Since your son is 14 years old I am a bit concerned. regards. Jay Indravadan Patel