What he said is accurate. Rotator cuff strains involve tears of the muscle fiber and sprains involve tearing or stretching of the ligaments. Both can be problematic and both can be very minor and heal on theit own. Generally rest is the best medicine for a strain. Minor strains can feel better sometimes after a few days of rest major ones he may not be able to lift his arm. Let's hope it is a minor strain. So he is in full swing for the tourney. I do agree, if it is on the fence they may decide to give him the extra rest so he is in full swing for the ncaa tourney. I would rather have him in good shape for the 4/5 ncaa game than play 70% up until that point and then because of inflammation he can't play in the second round.
This has been covered previously, but here is a definition by the Mayo Clinic:
http://www.mayoclinic.org/diseases-conditions/sprains-and-strains/basics/definition/con-20020958
"A sprain is a stretching or tearing of ligaments — the tough bands of fibrous tissue that connect two bones together in your joints."
"A strain is a stretching or tearing of muscle or tendon."
I don't claim to be a human medical doctor, nor would I assume to be the authoritative source on musculoskeletal injuries, but I do disagree with his definition, as well as your statement. However, we may be arguing semantics in the sense of what you mean by "a tear" (microscopic versus macroscopic).