Good question - it hard to put an accurate time on it, but a line in the sand would be something like. 1) Partial grade 1 tear 2-3 weeks (not super serious, but enough to knock you out for a couple of weeks) 2) Grade 2 tear, larger tear, more pain during rest with time off extending up to 6 weeks. If you have a significant tear, and pushing reasonable weight ie. >80% of your total body weight, then you will be out for longer as your chance of re-injury goes up siginifcantly. You have to ease back into it and find someone that can guide your rehab. You can still train other areas of your body, but while your shoulder is compromised - an early return to lifiting is only going to extend your time off 100% effort. The other concern is the state of your shoulder stabilisers, without those the risk of injury goes up some more.