Tricky rib injury

So I've been dealing with this rib injury since about december. I'll stay away from training until it feels good (6 weeks or so last time) and when I go back to rolling it pops all over again. My question is this: How do I know when I'm really ready to start training again?

It took me two months before I could get back in the gym and do drills. Even then I was tentative and rolling light. But I had the same injury, I could not sleep on my back/stomach/left side. It was horrible.