Keeping Shape/Mass Through Injury

Hi guys,
I am a former pro rugby player, now semi-pro rugby league. I have had both knees reconstructed, a double hernia, fused L5 S1, several spine surgeries and many more injuies. Injuries have prevented me from becoming a successfull consistent professional.
Anyway, I have torn my groin. My whole pubic area is agony and the area over my left hernia is agony too. I pride myself on my physique, and my strength and fitness has gotten me where I have been in my sport. Contracting my abs has been sore since the injury 2 months ago (I had 2 local anaessthetic jags during the game and was on crutches for 3 weeks).
I NEED to keep in shape, but am struggling. I am and always have been clean ( subject to testing too). I have been lifting light and no aggravation, only chest is tough as you really need your core for bench, presses etc.
Does anyone have any advice, I have been using painkillers to train even though it is light. I have been doing my rehab, but nothing is working. I may need some cortisone.
Also I have been told I am naturally genetically gifted, and should pursue bodybuilding. Due to my treatment in pro rugby, I am now considering it, but would go natuatal. Again, any advice? Links to good articles on training regimes to have mass yet remain ripped would be good too.
Thnaks for having me guys, and look forwatrd to becoming part of the community