Okay – this will sound really odd, and probably best to do in warm weather. Bring out a chair of some sort and a book. Sit out there, read and ignore him. Horses mostly do not want to be ignored. If he comes to you, say hi, but do nothing else. Eventually, one hopes, he will eventually give up the other game in favor of getting you to play with him. Then, take him out of the field to hand graze that great stuff on the other side of the fence for awhile and put him back in his field. He will stop associating leaving the field with work or vets, etc., and should be more reasonable about being caught. Of course, you would have to vary your activities with him, so he doesn’t know what’s in store when you do get him. Another thing would be to go out, call him to you (obviously after he does come when you call), give him some treat or other, pet him and leave. It will likely take a longish period of time, during which perhaps when you do want him, try to have someone get him for you, so as not to interrupt the rehab.
It is never the horse's fault