have a rebuilt shoulder, no tendons it ligaments…the muscle screwed straight to the bone (a “Frankenstein surgery” from back in ‘88).
I do several extremely light warm up sets to loosen things up as best I can, watch weight vs form, and on the first sign of “bad pain” (vs good pain), I stop, or at minimum, take great pause and then go a lot lighter…
I also redo the “stretching style warmups” after I’m done…to make sure rotation and the like are primary focus.
Stretch really good before you start your shoulder workout or exercises that requires you to have to lift overhead or where the shoulder is the primary or secondary muscle being worked. Go lighter and you also may have to use the smith-machine. If you can go heavier make sure you have a good spotter.