An ultrasound exam would give you the answer you are looking for, or at least provide for a more educated guess to be made. As for bandaging his legs, I would reconsider it.
You want to develop strength in the tendons and other tissues, and bandages serve to weaken them, not strengthen them.
Neither wraps or boots can offer any significant support to tendons or ligaments. this is well researched and proven. In order to provide the kind of tendon/ligament support necessary to actually prevent overstretch injuries and tears, a rigid cast or splint is needed, which would not allow for mobility and function.
So, the only reason for wraps or boots is to protect against blunt force trauma as with interference injuries. The risks of these injuries should be weighed against the risks posed by overheating of the tendons. there is a critical heat threshold at the core of each tendon, and when that threshold is exceeded, cellular degeneration and death begins. Severe, irreversible damage to the tendons may result. Also, overheated tendons are fatigued, and fatigue predisposes to acute injuries. When there is a history of healed tendon injury, that is an area of weakness that is more vulnerable to injury associated with fatigue.
So, since wraps and boots prevent dissipation of heat through exposure to airflow and evaporation of sweat, the critical threshhold will be reached that much sooner. this risk should be considered when you decide whether or not to use leg wraps or boots. If they are needed, then it is good practice to periodically remove them to cold hose the legs and cool the tendons. Always remove them after heavy workouts and cold hose if needed.
Ideally, you would have the tendon examined by ultrasound to assess the nature of healing. There can be a wide variation in the pattern of fibers and scarring from one injury to the next, with some less vulnerable to reinjury than others. Typically it is best to do your conditioning without bandaging the legs, unless you need to prevent blunt force trauma.
I hope you are increasing his dietary fat as an energy source, and not upping the nonstructural carbohydrates in his diet. By adapting him to metabolizing increased dietary fats as an energy source during conditioning, and well in advance of competition, his ability to sustain muscle function throughout endurance competition will be considerably improved.
Here is a quick study on the types of muscle fibers and their functions in both aerobic and anaerobic muscle metabolism. Note that thoroughbreds have a predominance of fast twitch fibers that are more efficient for anaerobic muscle metabolism beneficial to short distance bursts of speed at the track. By increasing dietary fat consumption and instituting a carefully designed program of conditiioning, more slow twitch fibers can be developed to allow for the aerobic muscle metabolism that is beneficial in long distance endurance competition.