I'm hoping I don't have to. If I have to give up playing USTA leagues and tournaments, I will at least continue to coach my daughters and wife, but that's not the same.
The ACI is intended to replace cartilage that is missing in my knee. Rest may help, as would losing weight (I'm not really overweight but being leaner definitely helps your knees). Building up muscle helps prevent tears and other issues, but won't help with what is essentially a bone-on-bone problem.