Ouch !! That is a tough injury just before season - hope it heals quick and you can get the shooting groove back.  I have a good friend that had shoulder surgery and it was a few months recovery and rehab before he could get good groups.  You are right, just don't over do it.  The good thing is you don't need to shoot a group to kill an animal at 25 yards.  If you are shooting 4 good ones that is all you need.  I have friends that will shoot alot of arrows in a session and then they get shakey and start spraying arrows all over the place and getting into bad habits.  I used to do the same.  Now I shoot for accuracy and rarely shoot more than 12 arrows in a session.  I do other strength training so I can hold the bow back for 2 minutes plus and still shoot well.   Best of luck -