My senior year of high school I herniated two discs in my low back during February. I ended up having to skip out on the majority of my senior year. My case was pretty extreme though compared to others. My injury was at the point where I could not even bench press without pain shooting from my low back down to my legs.
My doc basically told me in March that if I didn't stop throwing now, my back was going to be in even more pain by the time I got to Michigan. Like Antonio said it's a serious injury and not one to mess with. My advice to you is that if you decide to go ahead and throw this year, just make everything about technique. If it doesnt hurt you to throw, go for it. Its the weight room that can get you into trouble with an injury like that. For me it has been over a year, and my back still hasnt made a 100 percent recovery. Just be careful in the weight room (do things that don't hurt), strengthen the core, and work the circle! You can definitely still have a memorable season with a herniated disc as long as you treat it carefully.
Best of luck