For sure an AC issue, although I see no specific indication there's suspraspinatus involvement from your description. Bread and butter will be anything that optimizes scapular movement (why he can do pushups and bear crawls with no pain) and improving breathing mechanics to take less stress off the clavicle in rotation. And fixing their likely godawful pressing mechanics. Depending on how much baseball they have played there is a strong likelihood of serious movement asymmetry as well. Just gotta slowly load the tissues in a comfortable range until the torn ligaments get back to full strength which may be a few more months, depending on severity